release: 0.93.1 (bug/preview-crashes-the-tracker)

The composer's preview did not fail a call — it killed the Gitea process, and
with it the git server and the container registry. `POST /api/v1/markdown` with
`{"Mode": "gfm", "Context": "<repo>"}` makes Gitea resolve every hex-shaped word
as a commit link, and on the API's render path the commit checker it asks is nil:

  panic: runtime error: invalid memory address or nil pointer dereference
  renderhelper.(*commitChecker).IsCommitIDExisting(0x0)
   <- markup.hashCurrentPatternProcessor (html_commit.go:217)

Every report carries hex — a tab id, a request id — so this was not an edge case
but the only case: the preview answered "the tracker isn't answering" every time,
because the tracker had just died.

Measured on throwaway instances, not argued. Same body, same call:
  gfm + Context + "5645b1c0ae01"  -> 1.26.4 CRASH, 1.27.1 CRASH, 1.27.3 200
  gfm + Context, no hex           -> 200
  gfm, no Context                 -> 200, and the HTML keeps its tables, task
                                     lists and chroma-highlighted code blocks
Upstream fixed it in 1.27.2 ("fix: avoid markup render panic", #38698), but a
self-hoster runs whatever version they run, so the payload is what gets fixed.

Sending was never affected: the created issue's own page renders the same body
fine (measured) — a real repo context has a real commit checker. The only loss is
that a hash or a `#123` is not yet a link in the preview; the issue page links it.

The test pins the payload dict, because the defect is in what we send.

CHANGELOG.md

@@ -7,6 +7,115 @@ edit the release notes and re-run the generator.
 
 Upgrading, pinning a version and rolling back: [docs/self-hosting.md](docs/self-hosting.md#upgrading).
 
+## 0.93.1 — 2026-09-20
+
+The report composer's preview works again.
+
+### Fixes
+
+- Looking at a report before sending it said "the issue tracker isn't answering" — every time, for everyone. The preview asked the tracker to resolve links against the repository, and a report always carries something that looks like a commit hash: an id of the tab, of a request. On a tracker older than Gitea 1.27.2 that request does not fail, it stops the tracker — so the preview now asks for the rendering without the repository, which shows the same tables, lists and code, and can no longer take a tracker down. Sending a report was never affected.
+
+## 0.93.0 — 2026-09-20
+
+A way to report a fault from inside the app: record what you did, mark the steps, attach screenshots — and the app writes the report for you, with the logs of exactly that session attached.
+
+### Features
+
+- Start a recording (the command palette, or Settings → Diagnostics) and a pill follows you: a timer, “Step” to mark what you just did, a screenshot button, and Stop. Everything you and the server do while it runs is collected under that one session, and nothing else is.
+- Stop opens the composer: a drafted title and description, the steps you marked interleaved with the pages you visited, a table of your browser and the app's version, and the attachments — each one reviewable, each one removable.
+- The log lines that would be sent can be read before they go, line by line, and any of them left out.
+- Screenshots come from a paste, a drop, a file, or capturing the tab — up to eight, and any of them can be dropped again before sending.
+- Send opens an issue on the project's tracker with the report and its logs attached, and the preview shows it exactly as the tracker will render it. Five reports an hour.
+- Without a tracker configured — or whenever you would rather keep it — the same report downloads as a zip instead.
+- An administrator sets the tracker up in Settings → System (address, repository, token) and can test the connection there. The server refuses to send to a public repository: a report carries its reporter's log.
+
+### Fixes
+
+- The Plex player keeps the keyboard inside itself: Tab no longer walks out of a playing film into the page behind it, not even while its own settings panel is open.
+- A report cannot be sent twice at once, from any tab: while one send runs the others say so, and a send that fails half-way retries only what is missing — never a second issue.
+- A recording ends by itself after an hour, and both Stop and that hour return your diagnostics level to whatever it was before you started.
+
+### Internal
+
+- A session's logs and screenshots are purged with the session after 7 days, like every other diagnostic line, and another account's session id is ignored rather than refused.
+- Four adversarial review rounds at the epic's end: 80 findings fixed across them, every regression test proven to fail with its own fix removed, and the keyboard and focus work measured in a real browser rather than argued.
+
+## 0.92.0 — 2026-09-19
+
+A debt burn: every item the roadmap had deferred is done or dropped — Plex playback per viewer, refusals said in your language, controls that keep the keyboard focus, and a screen reader that hears Hungarian.
+
+### Features
+
+- The command palette has a visible way in: a Ctrl K key cap in the header's search field, and a “Jump to…” pill on pages without one.
+- The Playlists rail says, under “Missing a list? Why?”, which lists YouTube's API does not hand out (Watch later, History, lists saved from other channels).
+- The last native drop-downs are the app's own controls: the live search's result count, rows per page, a download format's content, audio format and quality, and the download dialog's format.
+- Plex plays one session per viewer, so two accounts can watch the same film at once; an administrator sets the ceiling on concurrent sessions (Configuration → Plex).
+
+### Fixes
+
+- A YouTube action YouTube refuses says what to do — wait for tomorrow's quota, reconnect the account, or try again later — instead of a server error; a passing Google hiccup no longer asks you to reconnect.
+- Every refusal the server gives is said in your language, and every label a screen reader or tooltip reads is translated.
+- Dragging to reorder a list is announced in your language and with the right position, and a Plex playlist keeps a drag within the list it started in.
+- A button that turns itself off, or a row that removes itself, leaves the keyboard focus where it was; Back from a Plex title returns the focus to the tile you opened, even after using a button there.
+- With Plex turned off, the Home shelf shows your YouTube pins only, and reordering it leaves the hidden Plex pins in their places; two reorders at once can no longer put two pins on one slot.
+- The Home hero from a pinned show offers to unpin the show, and “Surprise me” from the command palette really asks for a surprise.
+- A finished Plex title scrobbles once and gets no resume point pushed after it; a subtitle pass that stalled resumes instead of starting over.
+- Tables keep their j/k keys after the window is resized across the phone breakpoint, and boxes grow with the text-size setting.
+- Whitelisting an address and activating its account happen in one step, and the audit log names the entry.
+
+### Internal
+
+- Every mutation answers `ok`, and route helpers leave the commit to the request — both held by tests; a request that leaves a write uncommitted now fails its test.
+- New lint rules and contracts: no native select, no hover that ignores aria-disabled, no untranslated accessible text, no unused translation key.
+- Two adversarial review rounds at the epic's end: 23 findings, all fixed, each regression test proven to fail with its own fix removed.
+
+## 0.91.0 — 2026-09-19
+
+What a test run on the live instance turned up, fixed: new videos keep arriving while YouTube's feeds are down, an open tab survives a release, and Back returns to what you left.
+
+### Features
+
+- A card's menu (right-click or long press) now offers the card's own actions — watched, save, hide, reset — beside the comfort-shelf pin.
+- Settings → Account shows your role and your last sign-in. 0.88 announced the last sign-in in your account panel; it is actually there now.
+
+### Fixes
+
+- When YouTube's feed for a channel stays dark for hours, as it did for 393 of 396 channels on 18–19 September, the channel's newest uploads are read through the YouTube API instead, at most once every 2 hours per channel (adjustable by an administrator, 0 turns it off).
+- A tab left open across a release no longer falls to the crash screen when it opens something it had not loaded yet: it reloads onto the new version once.
+- Back from a request's lines in the Server log returns to the view the pivot was made from, search text included, as 0.90 promised.
+- Back to Home keeps the question you asked (the time budget and the hero you rerolled to), and the keyboard lands on the card you opened, even when the rail's cards moved or several share a name.
+- Browser tabs are named after the page again: signed out, and on the privacy and terms pages.
+- On a phone, the feed and Plex toolbars wrap instead of running past the edge, and so do notifications.
+- The countdown of a raised diagnostics level counts from the moment it was raised, not from when the page was opened.
+- The download box's placeholder names every site it takes, Facebook included.
+
+### Internal
+
+- The screens' own polling reads (the unread badges, the download list, the scheduler) are logged at debug level in the server's log and in the browser's copy of it, where they made up about 95% of the lines.
+- An account with no YouTube channel no longer writes a warning every six hours, and a scheduler job that fails carries an event code.
+- Two adversarial review rounds: 15 findings raised, 11 survived, all fixed, and every regression test was proven to fail with its own fix removed.
+
+## 0.90.0 — 2026-09-19
+
+The server's log gets a screen of its own: an admin can now read what the API, the downloader and the browsers wrote down, filter it, and follow one request or job from start to end.
+
+### Features
+
+- Admin → Server log: the stored log, newest first, with a search, level chips, and source, account, event and period filters. A line opens in place to its full record; its request id or job id narrows the list to everything that request or job wrote.
+- Filters live in the address bar, so a filtered view is a link, and Back brings the previous view back.
+- Live follows the newest lines every few seconds; Copy puts the loaded lines on the clipboard, oldest first. A failed read says so instead of quietly freezing the list.
+- Both log viewers (Server log and My log) can be walked with j/k and a line opened with Enter.
+
+### Fixes
+
+- New videos no longer arrive late from channels whose YouTube feed answers 404 or 500 now and then: a feed is tried again before the channel counts as failed.
+- A % or _ typed into a search is searched for as itself, not as a wildcard.
+
+### Internal
+
+- The console's own reads are logged at debug level, so watching the log does not fill it.
+- Two adversarial review rounds: 19 findings raised, 12 survived, all fixed, and every regression test was proven to fail with its own fix removed.
+
 ## 0.89.0 — 2026-09-19
 
 A release for the log rather than for the screen: what the server writes down when something fails is now complete, said once, and free of what you downloaded or searched for.

CLAUDE.md

@@ -56,9 +56,9 @@ how it gets built. Concretely:
 ## Architecture shape (don't fight it)
 
 `routes/*` (HTTP only: validation, auth-dependency, serialization) → domain packages `sync/`, `plex/`,
-`downloads/`, `youtube/` (shared by routes + scheduler + worker) → flat core (`auth`, `quota`,
+`downloads/`, `youtube/`, `issues/` (shared by routes + scheduler + worker) → flat core (`auth`, `quota`,
 `sysconfig`, `state`, `audit`, `notifications`, `userscope`, `realtime`, `ratelimit`, `progress`,
-`security`, `logs`, `logsink`, `diagnostics`) → `models/db/config`. **Dependency direction is one-way: core never imports routes.**
+`security`, `logs`, `logsink`, `diagnostics`, `debugsession`) → `models/db/config`. **Dependency direction is one-way: core never imports routes.**
 Frontend: `main.tsx` provider tree → `App.tsx` shell → `moduleRegistry` route-chunks → module
 components → the **platform layer `components/ui/`** (domain-free primitives: the popover engine and
 its menus, `Modal`/`Overlay`, `Button`/`form`, `DataTable`/`VirtualGrid`, `QueryState`, …). That
@@ -82,8 +82,8 @@ CQRS, a repository/DI framework, a router library, a generic CRUD-router factory
 | Admin gate import       | `app.auth`                                                   | the `app.routes.admin` re-export                       |
 | Upstream failure status | `422` with JSON detail                                       | `502` (reserve 502 for raw byte-proxies)               |
 | User-facing error       | structured `detail` (`{code, reason}`)                       | a bare English string under a bilingual UI             |
-| Mutation response       | `{"ok": true, …}` (`{"deleted": id}`)                        | ad-hoc `{"unsubscribed"}`/`{"cleared": n}`/echo        |
-| Transaction commit      | the handler/job-wrapper commits; helpers `flush`             | helpers that commit (only `quota` owns its session)    |
+| Mutation response       | `{"ok": true, …}` (`{"deleted": id}`), test-held             | a bare `{"unsubscribed"}`/`{"cleared": n}`, no `ok`    |
+| Transaction commit      | the handler commits; helpers `flush` (test-held list)        | helpers that commit (only `quota` owns its session)    |
 | Admin knob storage      | `sysconfig` (values)                                         | env / `app_state` / `scheduler_settings` scatter       |
 | Job status word         | the `downloads/status.py` StrEnum                            | loose `"canceled"`/`"cancelled"` literals              |
 | Current time            | inline `datetime.now(timezone.utc)`                          | new `now_utc`/`_now` helpers                           |
@@ -92,7 +92,7 @@ CQRS, a repository/DI framework, a router library, a generic CRUD-router factory
 | FE keyboard shortcut    | a row in `lib/keymap.ts` + `dispatch()`                      | a private `keydown` listener with its own key literals |
 | FE list/grid keys       | `NavGrid`/`keyboardNav` + `navItemAttrs` + `data-nav-open`   | a private arrow-key / roving-tabindex handler          |
 | FE view push (history)  | `rememberNavPosition()` right before `history.pushState`     | a push that forgets: Back strands focus on `<body>`    |
-| FE control              | the chip/segmented primitives (`Select` only for >6 options) | a native `<select>`                                    |
+| FE control              | `SegmentedToggle`; a long or user's list: `FilterSelect`     | a native `<select>` (lint-enforced)                    |
 | FE loading/empty/error  | `QueryState` / `StateMessage`                                | ad-hoc conditionals                                    |
 | FE failed write         | `meta.failTitle`, else `notifyActionError(err, title)`       | a bare `catch {}` or `notify()` with no error attached |
 | FE network call         | `req`/`uploadReq`/`beacon`, or `lib/http.ts` `send` (public pages) | a bare `fetch`/`XMLHttpRequest`/`WebSocket` (lint-enforced) |

VERSION

@@ -1 +1 @@
-0.89.0
+0.93.1

backend/alembic/versions/0088_channels_feed_fallback_at.py

@@ -0,0 +1,30 @@
+"""add channels.feed_fallback_at — when a channel's uploads were last read through the API because
+its RSS feed would not answer
+
+Revision ID: 0088_channels_feed_fallback_at
+Revises: 0087_users_diagnostics_level
+Create Date: 2026-09-19
+
+YouTube's RSS feeds go dark for hours at a time, per channel (2026-09-18/19: 393 of 396 answered 404
+for four hours; the same channel answers 404 to every retry). The RSS poll then reads the newest
+uploads through the Data API instead, at a quota cost, and at most once per `rss_fallback_hours` per
+channel: this column is that clock. NULL = never needed it.
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0088_channels_feed_fallback_at"
+down_revision: str | None = "0087_users_diagnostics_level"
+branch_labels: str | None = None
+depends_on: str | None = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "channels", sa.Column("feed_fallback_at", sa.DateTime(timezone=True), nullable=True)
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("channels", "feed_fallback_at")

backend/alembic/versions/0089_debug_sessions.py

@@ -0,0 +1,81 @@
+"""add debug_sessions + debug_screenshots, and index log_events.debug_session_id (E16)
+
+Revision ID: 0089_debug_sessions
+Revises: 0088_channels_feed_fallback_at
+Create Date: 2026-09-19
+
+A debug session is one recording: Start → reproduce → Stop (app/debugsession.py). Every log line
+of that user's requests while it runs carries its id in `log_events.debug_session_id` — the column
+E22 created and left NULL — and the issue it ends in is built from exactly those rows, so the column
+gets its index now. Partial: nearly every row has no session, and an index of NULLs would be most
+of the table for nothing.
+
+At most one OPEN session per user, held by a partial unique index rather than by the start handler
+alone: two tabs pressing Start at once would otherwise both pass a "none open" check.
+
+Screenshots are rows, not files: bounded (size and count per session, app/debugsession.py), gone
+with their session by cascade, and a self-host has no file volume to configure for them.
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0089_debug_sessions"
+down_revision: str | None = "0088_channels_feed_fallback_at"
+branch_labels: str | None = None
+depends_on: str | None = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "debug_sessions",
+        sa.Column("id", sa.String(16), primary_key=True),
+        sa.Column(
+            "user_id",
+            sa.Integer,
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+            index=True,
+        ),
+        sa.Column("level", sa.String(8), nullable=False),
+        sa.Column("started_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("until", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("ended_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("ended_reason", sa.String(16), nullable=True),
+        sa.Column("issue_url", sa.String(512), nullable=True),
+    )
+    op.create_index(
+        "uq_debug_sessions_open_per_user",
+        "debug_sessions",
+        ["user_id"],
+        unique=True,
+        postgresql_where=sa.text("ended_at IS NULL"),
+    )
+    op.create_table(
+        "debug_screenshots",
+        sa.Column("id", sa.Integer, primary_key=True),
+        sa.Column(
+            "session_id",
+            sa.String(16),
+            sa.ForeignKey("debug_sessions.id", ondelete="CASCADE"),
+            nullable=False,
+            index=True,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("mime", sa.String(16), nullable=False),
+        sa.Column("size", sa.Integer, nullable=False),
+        sa.Column("data", sa.LargeBinary, nullable=False),
+    )
+    op.create_index(
+        "ix_log_events_debug_session",
+        "log_events",
+        ["debug_session_id"],
+        postgresql_where=sa.text("debug_session_id IS NOT NULL"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_log_events_debug_session", table_name="log_events")
+    op.drop_table("debug_screenshots")
+    op.drop_index("uq_debug_sessions_open_per_user", table_name="debug_sessions")
+    op.drop_table("debug_sessions")

backend/alembic/versions/0090_debug_session_draft.py

@@ -0,0 +1,27 @@
+"""add debug_sessions.draft — the issue being written from a session (E16 S3)
+
+Revision ID: 0090_debug_session_draft
+Revises: 0089_debug_sessions
+Create Date: 2026-09-19
+
+The composer saves as it goes: the title, the rendered markdown body that an export or an issue
+carries, the log rows the user took out, and the form's own fields so reopening it later (Settings →
+Diagnosztika lists past sessions) shows what was written. NULL until the composer first saves.
+"""
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects.postgresql import JSONB
+
+revision: str = "0090_debug_session_draft"
+down_revision: str | None = "0089_debug_sessions"
+branch_labels: str | None = None
+depends_on: str | None = None
+
+
+def upgrade() -> None:
+    op.add_column("debug_sessions", sa.Column("draft", JSONB, nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("debug_sessions", "draft")

backend/app/README.md

@@ -13,16 +13,17 @@ Three layers, by *who* runs the code — not by feature:
    response models, status-code mapping, serialization. It owns logic that runs *only* on a request.
    Business logic that a request happens to trigger does **not** live here if anything else runs it too.
 
-2. **`plex/`, `downloads/`, `sync/` — domain logic shared by more than one caller.** Anything the
+2. **`plex/`, `downloads/`, `sync/`, `issues/` — domain logic shared by more than one caller.** Anything the
    **scheduler or the worker** runs (not just a request) lives in one of these domain packages, so the
    route, the worker, and the scheduler share one definition. Examples from this codebase:
    `downloads/service.py` owns enqueue + the job state transitions (routes call it); `plex/sync.py` is
-   run by both the admin route and the scheduler; `downloads/pipeline.py` is the worker's child pipeline.
+   run by both the admin route and the scheduler; `downloads/pipeline.py` is the worker's child pipeline;
+   `issues/bundle.py` is the one definition of a bug report's files, for the zip export and the tracker.
 
 3. **Flat `app/*.py` core modules — cross-cutting primitives.** `auth`, `sysconfig`, `quota`, `audit`,
    `notifications`, `userscope`, `realtime`, `ratelimit`, `progress`, `logs` (the one logging
-   configuration), `logsink` (its `log_events` table) and `diagnostics` (a user's consented log
-   level), … are single-file primitives many layers import. They depend on nothing above them (a core
+   configuration), `logsink` (its `log_events` table), `diagnostics` (a user's consented log
+   level) and `debugsession` (a recording that tags its user's lines, E16), … are single-file primitives many layers import. They depend on nothing above them (a core
    module must never import a `routes/…` module).
 
 **Extraction trigger: the SECOND consumer.** Keep new logic inline in its first caller. The moment a

backend/app/audit.py

@@ -58,6 +58,9 @@ class AuditAction:
     DOWNLOAD_CREDENTIAL_DELETE = "download_credential_delete"
     # The log itself was cleared (a single row survives the clear as tamper-evidence)
     AUDIT_CLEAR = "audit_clear"
+    # E16: a user sent a debug session's issue to the tracker — the one act that takes their log
+    # off this instance, so it is recorded (target = the session, summary = the issue's URL).
+    ISSUE_CREATE = "issue_create"
 
 
 def record(

backend/app/auth.py

@@ -4,7 +4,7 @@ from sqlalchemy import delete, func, select
 from sqlalchemy.orm import Session
 from starlette.requests import HTTPConnection
 
-from app import diagnostics
+from app import debugsession
 from app import email as email_mod
 from app import logs
 from app import mailtext
@@ -14,6 +14,7 @@ from app.db import get_db
 from app.models import Invite, LogEvent, User
 from app.security import decrypt_optional
 from app.utils import canonical_email
+from app.refusal import refused
 
 PASSWORD_MIN_LEN = 10
 
@@ -341,19 +342,19 @@ def current_user(request: Request, db: Session = Depends(get_db)) -> User:
 
 def _session_user(request: Request, db: Session, user_id: int | None, is_default: bool) -> User:
     if not user_id:
-        raise HTTPException(status_code=401, detail="Not authenticated")
+        raise refused(401, "not_authenticated")
     user = db.get(User, user_id)
     if user is None or not user.is_active or user.is_suspended:
         # Suspended/deactivated mid-session → end it so the block takes effect at once.
         _end_account_session(request, user_id, is_default)
-        raise HTTPException(status_code=401, detail="Not authenticated")
+        raise refused(401, "not_authenticated")
     # SA4: reject a cookie whose recorded epoch is behind the account's current one (revoked by a
     # password reset/change or "log out everywhere"). A cookie with no recorded epoch (pre-SA4, or an
     # account signed in before this shipped) is treated as epoch 0 — so the FIRST bump revokes it too.
     epochs = request.session.get("epochs") or {}
     if int(epochs.get(str(user_id), 0)) != (user.session_epoch or 0):
         _end_account_session(request, user_id, is_default)
-        raise HTTPException(status_code=401, detail="Not authenticated")
+        raise refused(401, "not_authenticated")
     # Always keep the session default in the switchable list — covers sessions created before
     # multi-session existed (their account_ids was never seeded), so the switcher isn't empty.
     default_id = request.session.get("user_id")
@@ -366,7 +367,11 @@ def _session_user(request: Request, db: Session, user_id: int | None, is_default
     # session middleware and this task's context. `request.state` is shared across middleware layers
     # (it lives on the ASGI scope), so the access-log line can read it back. The user's consented
     # diagnostics level rides along: their requests are logged — and stored — in that detail (S5).
-    logs.set_user(user.id, diagnostics.effective_level(user), user.diagnostics_until)
+    # So does a debug session the request names (E16): only the caller's own open one counts, and a
+    # header naming anything else is ignored rather than refused — a stale tab must keep working.
+    session = debugsession.from_header(db, user, request.headers.get(debugsession.HEADER))
+    level, until = debugsession.level_for(user, session)
+    logs.set_user(user.id, level, until, session.id if session else None)
     request.state.user_id = user.id
     return user
 
@@ -418,10 +423,7 @@ def require_write_scope(user: User = Depends(require_human)) -> User:
     checks that had drifted into three different 403 messages across channels/playlists. Layers on
     `require_human` because writing to YouTube needs a real, non-demo identity."""
     if not has_write_scope(user):
-        raise HTTPException(
-            status_code=403,
-            detail="Enable YouTube editing in Settings first.",
-        )
+        raise refused(403, "youtube_editing_off")
     return user
 
 
@@ -429,7 +431,7 @@ def admin_user(user: User = Depends(current_user)) -> User:
     """Dependency: require the signed-in user to be an admin. Single source of truth for the
     admin gate — every admin route/action depends on this rather than re-checking the role."""
     if user.role != "admin":
-        raise HTTPException(status_code=403, detail="Admin only")
+        raise refused(403, "admin_only")
     return user
 
 

backend/app/config.py

@@ -119,6 +119,9 @@ class Settings(BaseSettings):
     # Recent-first backfill: how far back to fetch on the first pass per channel.
     backfill_recent_max_videos: int = 100
     backfill_recent_max_days: int = 365
+    # A channel whose RSS feed has not answered for this many hours gets its newest uploads read
+    # through the Data API instead (1 unit), at most once per this many hours. 0 = never.
+    rss_fallback_hours: int = 2
 
     # Shorts are confirmed by probing youtube.com/shorts/<id>. Only videos at or below
     # this duration (and not livestreams) are probed; longer videos are never Shorts.
@@ -312,6 +315,10 @@ class Settings(BaseSettings):
     # re-encode is CPU-heavy (the VAAPI hardware path is far cheaper and could sustain more); direct-serve
     # and remux (stream-copy) are not capped by this.
     plex_max_transcodes: int = 4
+    # Max concurrent playback sessions of ANY kind — remux (stream-copy) included. Cheap on the CPU but
+    # each one is a whole segmented copy of the film on the scratch volume, written faster than
+    # realtime. One account holds at most two regardless (plex/stream.py `_MAX_SESSIONS_PER_USER`).
+    plex_max_sessions: int = 8
     # --- Transcode (playable="transcode") re-encode tuning (E6 S1) ---
     # Hardware-encoder policy: "auto" = VAAPI (h264_vaapi) when the iGPU render node is present AND the
     # source codec is hardware-decodable, else libx264 software; "on" = force VAAPI wherever the render
@@ -344,6 +351,13 @@ class Settings(BaseSettings):
     tmdb_api_base: str = "https://api.themoviedb.org/3"
     # Metadata language for TMDB fetches (keyword/overview locale). Stored EN by default.
     tmdb_language: str = "en-US"
+
+    # --- Bug reports (E16): where a debug session's issue goes. All three empty = no tracker; the
+    # composer still exports a zip. The repository must be PRIVATE — an issue carries the reporter's
+    # log — and app/issues/gitea.py refuses a public one. Runtime knobs (sysconfig, admin UI). ---
+    issues_gitea_url: str = ""
+    issues_gitea_repo: str = ""
+    issues_gitea_token: str = ""
     # How often the TMDB enrichment job fetches a batch of not-yet-enriched Plex titles, in minutes.
     tmdb_enrich_interval_min: int = 120
     # Titles fetched per TMDB enrichment run (TMDB is fast + generously rate-limited).

backend/app/debugsession.py

@@ -0,0 +1,485 @@
+"""Debug sessions (E16): Start → reproduce → Stop, and the evidence a bug report is built from.
+
+While a session is open its user's browser names it in `X-Debug-Session` on every request. The auth
+dependency accepts the header only for the caller's OWN open session (anything else is ignored, never
+an error — a stale tab must not break the app) and then logs that request at the session's level with
+every line tagged by its id; the browser tags its own events the same way. The issue is later built
+from exactly the rows carrying the tag, so what the review list shows is what gets sent.
+
+Starting a session IS the consent for its level, for its duration: the start dialog carries the
+consent text. It needs no change to the user's own diagnostics level, and none is made — when the
+session ends the level in force is simply the user's own again.
+
+A session is capped at `MAX_MINUTES`, set by the server at Start. An open one past its cap is over
+whether or not anything has closed it yet: it reads as over at once, a new Start closes it, and the
+hourly log job sweeps the rest. Sessions go with the logs they point at, after `log_retention_days`.
+
+Core layer: imports `models`, `diagnostics`.
+"""
+
+import secrets
+from datetime import datetime, timedelta, timezone
+from enum import StrEnum
+from typing import Literal, get_args
+from uuid import uuid4
+
+from sqlalchemy import and_, delete, func, not_, select, update
+from sqlalchemy.orm import Session, defer
+
+from app import diagnostics
+from app.models import DebugScreenshot, DebugSession, LogEvent, User
+
+HEADER = "x-debug-session"
+MAX_MINUTES = diagnostics.SESSION_MINUTES
+SCREENSHOT_MAX_BYTES = 10 * 1024 * 1024
+SCREENSHOTS_MAX = 8
+# What one user may keep in screenshots across ALL their sessions (until retention takes them): the
+# per-session cap alone would let Start → 8 images → Stop repeat without end.
+SCREENSHOT_USER_MAX_BYTES = 100 * 1024 * 1024
+# The screenshot types kept, and the extension each is exported and sent under — one table, so an
+# accepted type always has a name.
+IMAGE_TYPES = {"image/png": "png", "image/jpeg": "jpg", "image/webp": "webp"}
+# What a screenshot is called in the zip and on the issue. `issues/bundle.py` builds the names from
+# this and `IMAGE_TYPES`; this module and `issues/gitea.py` read them back to tell a screenshot's
+# link from a log's. One definition, because three copies of a name is how the next rename breaks
+# `images_pending` into silence.
+SCREENSHOT_PREFIX = "screenshot-"
+# Rows an issue can carry. A 60-minute session at Teljes is a few thousand rows; past this the
+# bundle says how many it left out rather than growing without bound.
+BUNDLE_MAX = 5_000
+
+SessionLevel = Literal["DEBUG", "TRACE"]
+SESSION_LEVELS: tuple[str, ...] = get_args(SessionLevel)
+# Detail order of the diagnostics levels: a session raises the level in force, never lowers it.
+_DETAIL = {"INFO": 0, "DEBUG": 1, "TRACE": 2}
+_ID_LEN = 16
+
+
+class EndReason(StrEnum):
+    STOPPED = "stopped"
+    EXPIRED = "expired"
+
+
+def is_live(session: DebugSession, now: datetime | None = None) -> bool:
+    """Open and within its cap — THE liveness rule: an open session past its cap is over."""
+    return session.ended_at is None and session.until > (now or datetime.now(timezone.utc))
+
+
+def open_session(db: Session, user: User) -> DebugSession | None:
+    """The user's live session, or None. Read-only: one past its cap is over and reads as None;
+    `start` and the hourly sweep are what close it."""
+    session = _unclosed(db, user)
+    if session is None or not is_live(session, datetime.now(timezone.utc)):
+        return None
+    return session
+
+
+def _unclosed(db: Session, user: User) -> DebugSession | None:
+    return db.scalar(
+        select(DebugSession).where(DebugSession.user_id == user.id, DebugSession.ended_at.is_(None))
+    )
+
+
+def start(db: Session, user: User, level: SessionLevel) -> DebugSession:
+    """Open a session, or return the live one — a second tab pressing Start joins the recording
+    rather than ending it. One past its cap is closed first: the one-open-per-user index would
+    refuse the new row beside it. Flushes; the caller commits. Two concurrent Starts can still both
+    get here: the index refuses the second, and the caller joins the one that won."""
+    now = datetime.now(timezone.utc)
+    current = _unclosed(db, user)
+    if current is not None:
+        if is_live(current, now):
+            return current
+        end(current, EndReason.EXPIRED)
+        db.flush()
+    session = DebugSession(
+        id=secrets.token_hex(_ID_LEN // 2),
+        user_id=user.id,
+        level=level,
+        started_at=now,
+        until=now + timedelta(minutes=MAX_MINUTES),
+    )
+    db.add(session)
+    db.flush()
+    return session
+
+
+def stop(session: DebugSession) -> None:
+    """The user's Stop. Past its cap the session had already ended on its own, and a late Stop must
+    not rename that."""
+    end(session, EndReason.STOPPED if is_live(session) else EndReason.EXPIRED)
+
+
+def end(session: DebugSession, reason: EndReason) -> None:
+    """Close a session. An expired one is dated at its cap, not at whenever it was noticed."""
+    if session.ended_at is not None:
+        return
+    session.ended_at = (
+        session.until
+        if reason is EndReason.EXPIRED
+        else min(datetime.now(timezone.utc), session.until)
+    )
+    session.ended_reason = reason
+
+
+def from_header(db: Session, user: User, value: str | None) -> DebugSession | None:
+    """The session a request names, if it is the caller's own and still live; else None."""
+    if not value or len(value) != _ID_LEN or not all(c in "0123456789abcdef" for c in value):
+        return None
+    session = db.get(DebugSession, value)
+    if (
+        session is None
+        or session.user_id != user.id
+        or not is_live(session, datetime.now(timezone.utc))
+    ):
+        return None
+    return session
+
+
+def level_for(user: User, session: DebugSession | None) -> tuple[str, datetime | None]:
+    """The diagnostics level (and its expiry) a request is logged at: the user's own, raised to the
+    session's while one is named — whichever records more.
+
+    A named session also caps the expiry at its own: this pair is what the process tracks under the
+    session (app/logs.py), and an expiry outliving the recording would hold the root logger down
+    after it ended."""
+    own = diagnostics.effective_level(user)
+    until = user.diagnostics_until if own != diagnostics.BASE else None
+    if session is None:
+        return own, until
+    if _DETAIL[session.level] <= _DETAIL[own]:
+        return own, min(until, session.until) if until else session.until
+    return session.level, session.until
+
+
+def lock(db: Session, session: DebugSession) -> None:
+    """Re-read the session under a row lock, held until the caller commits. Everything that changes
+    what an issue is made of — the draft, the screenshots, the send itself — takes it first: a send
+    in flight sees none of them change under it, and each of them sees a send that committed."""
+    db.refresh(session, with_for_update=True)
+
+
+def save_draft(session: DebugSession, draft: dict) -> None:
+    """Keep the composer's draft (the caller validated, locked and commits). Shape: `title`, `body`
+    (the rendered markdown an export or an issue carries), `excluded` (log row ids taken out of the
+    evidence) and `form` (the composer's own fields, to reopen it as it was). A delivery's progress
+    is not the composer's to replace, and is kept."""
+    progress = (session.draft or {}).get("delivery")
+    session.draft = {**draft, "delivery": progress} if progress else draft
+
+
+# --- a delivery's progress -----------------------------------------------------------------
+# Written by app/issues/gitea.py into the draft; read HERE, so the send's decision and what the
+# composer shows are one reading of it.
+def delivery(session: DebugSession) -> dict:
+    return dict((session.draft or {}).get("delivery") or {})
+
+
+def not_uploaded(session: DebugSession) -> list[str]:
+    """The files a send that stopped half-way has still to upload — by name, as the issue carries
+    them. What the composer names to the user."""
+    return list(delivery(session).get("pending") or [])
+
+
+def images_pending(session: DebugSession) -> bool:
+    """Whether the issue's body still has to be edited to show the screenshots it already carries
+    (every upload went, the edit that shows them did not)."""
+    state = delivery(session)
+    shown = state.get("images_shown")
+    return not shown and any(n.startswith(SCREENSHOT_PREFIX) for n in state.get("links") or {})
+
+
+def unfinished(session: DebugSession) -> bool:
+    """Whether a send owes the issue anything — the retry's question."""
+    return bool(not_uploaded(session)) or images_pending(session)
+
+
+# A send claims the session while it talks to the tracker, instead of holding the row's lock across
+# those calls: a Stop, an autosave or a screenshot would queue behind a lock for the whole send.
+# They see the claim and are refused at once instead. A claim not renewed for this long was left by
+# a request that died mid-send (the process restarted), and the next send takes it over — which is
+# why a live send RENEWS it every time it reports progress (`set_delivery`). A claim is a lease, and
+# a send slower than the lease must not lose it while it is still running.
+SEND_CLAIM_SECONDS = 600
+
+
+def _claim(session: DebugSession) -> dict:
+    claim = delivery(session).get("sending")
+    return claim if isinstance(claim, dict) else {}
+
+
+def _stamp(token: str) -> dict:
+    return {"at": datetime.now(timezone.utc).isoformat(), "by": token}
+
+
+def sending(session: DebugSession) -> bool:
+    """Whether a send is under way right now (a live claim)."""
+    at = _claim(session).get("at")
+    if not at:
+        return False
+    return (datetime.now(timezone.utc) - datetime.fromisoformat(at)).total_seconds() < (
+        SEND_CLAIM_SECONDS
+    )
+
+
+def claim_send(session: DebugSession) -> str:
+    """Mark the session as being sent, and return the token that OWNS this claim. The caller holds
+    the lock and commits, which is what makes the claim visible to everyone else."""
+    token = uuid4().hex
+    _write_delivery(session, {**delivery(session), "sending": _stamp(token)})
+    return token
+
+
+def release_send(session: DebugSession, token: str) -> None:
+    """Give back our OWN claim, and only ours: one that aged out and was taken over belongs to the
+    send holding it now, and handing that one back would let a third send in beside it."""
+    if _claim(session).get("by") != token:
+        return
+    _write_delivery(session, {k: v for k, v in delivery(session).items() if k != "sending"})
+
+
+class SendClaimLost(Exception):
+    """This send's claim is no longer on the row: it aged out and another send took it over. The
+    send must stop — what it uploads from here it can no longer record, so a retry would send it
+    again — and it must not write, because the row now holds the other send's progress."""
+
+
+def claim_owner(db: Session, session: DebugSession) -> str | None:
+    """Who holds the row's claim RIGHT NOW, read from the ROW and not from the object.
+
+    `expire_on_commit` is off (app/db.py), so a checkpoint does not re-read: a send that stalled
+    past its lease still carries its own dead token in memory long after another send took over.
+    A targeted scalar, not `lock`/`db.refresh` — a refresh here would discard the `issue_url` that
+    `gitea.deliver` assigns one line before its first progress report, and that link is the one
+    thing the send must not lose."""
+    return db.scalar(
+        select(DebugSession.draft["delivery"]["sending"]["by"].as_string()).where(
+            DebugSession.id == session.id
+        )
+    )
+
+
+def set_delivery(db: Session, session: DebugSession, state: dict, token: str) -> None:
+    """Write a delivery's progress (app/issues/gitea.py keeps it; this module reads it), and renew
+    the claim while doing it — a send still reporting progress is still alive, so one slower than
+    the lease cannot expire while it is still running.
+
+    The claim is not the caller's to carry: `gitea.deliver` threads ONE snapshot of this dict
+    through a whole send, so a progress report that carried the claim wrote a stale one back at
+    every step. It is stamped from `token` here instead, and only after the ROW confirms the claim
+    is still ours. Without that check the write is a full-column overwrite with no WHERE: a send
+    that lost its lease came back and stomped the take-over send's committed links, then put its
+    own dead token back on an idle session (deep-review round 4). `release_send` has always made
+    the same check; this is the other half of it."""
+    if claim_owner(db, session) != token:
+        raise SendClaimLost(session.id)
+    state = {k: v for k, v in state.items() if k != "sending"}
+    state["sending"] = _stamp(token)
+    _write_delivery(session, state)
+
+
+def _write_delivery(session: DebugSession, state: dict) -> None:
+    # A new dict, so the JSONB column sees the change.
+    session.draft = {**(session.draft or {}), "delivery": state}
+
+
+def serialize(session: DebugSession | None, screenshots: int = 0) -> dict | None:
+    if session is None:
+        return None
+    return {
+        "id": session.id,
+        "level": session.level,
+        "started_at": session.started_at.isoformat(),
+        "until": session.until.isoformat(),
+        "ended_at": session.ended_at.isoformat() if session.ended_at else None,
+        "ended_reason": session.ended_reason,
+        "issue_url": session.issue_url,
+        # A send that stopped half-way: the files it has still to upload, and whether the issue's
+        # body has still to be edited to show the screenshots it already carries. Both are true of a
+        # send that is RUNNING too — every step commits its progress — so `sending` goes with them:
+        # without it a reload or a second tab renders a live send as a failed one, and offers a
+        # retry that is certain to be refused.
+        "pending_files": not_uploaded(session),
+        "images_pending": images_pending(session),
+        "sending": sending(session),
+        "screenshots": screenshots,
+        "draft": session.draft,
+    }
+
+
+def view(db: Session, session: DebugSession) -> dict:
+    """The session as the API serves it — one shape wherever it is served."""
+    return serialize(session, screenshot_count(db, session)) or {}
+
+
+def screenshot_count(db: Session, session: DebugSession) -> int:
+    return (
+        db.scalar(
+            select(func.count())
+            .select_from(DebugScreenshot)
+            .where(DebugScreenshot.session_id == session.id)
+        )
+        or 0
+    )
+
+
+# --- screenshots ---------------------------------------------------------------------------
+# By content, not by the declared type: what is stored is served back to a browser as an image.
+_SIGNATURES = (
+    (b"\x89PNG\r\n\x1a\n", "image/png"),
+    (b"\xff\xd8\xff", "image/jpeg"),
+)
+
+
+def sniff(data: bytes) -> str | None:
+    """The image type `data` really is — one of IMAGE_TYPES — or None."""
+    for magic, mime in _SIGNATURES:
+        if data.startswith(magic):
+            return mime
+    if len(data) >= 12 and data[:4] == b"RIFF" and data[8:12] == b"WEBP":
+        return "image/webp"
+    return None
+
+
+def lock_user(db: Session, user_id: int) -> None:
+    """Hold this user's own lock for the rest of the transaction. A session's row lock bounds what
+    THAT session may keep; the byte cap below is the user's across all of them, and a lock on one
+    session cannot serialize a check that reads them all — two uploads to two sessions both read the
+    total before either commits, and both pass."""
+    db.execute(select(func.pg_advisory_xact_lock(user_id)))
+
+
+def stored_screenshot_bytes(db: Session, user_id: int) -> int:
+    return (
+        db.scalar(
+            select(func.coalesce(func.sum(DebugScreenshot.size), 0))
+            .join(DebugSession, DebugSession.id == DebugScreenshot.session_id)
+            .where(DebugSession.user_id == user_id)
+        )
+        or 0
+    )
+
+
+class ScreenshotRefused(Exception):
+    """A screenshot that cannot be kept; `code` is the refusal's machine word."""
+
+    def __init__(self, code: str) -> None:
+        super().__init__(code)
+        self.code = code
+
+
+def add_screenshot(db: Session, session: DebugSession, data: bytes) -> DebugScreenshot:
+    """Keep one screenshot. Locks the user and the session, and flushes; the caller commits.
+    Refused while a send is under way or once the issue was sent (it can no longer carry it), past
+    the per-session count or the user's storage, or when it is not an image we can show."""
+    if not data:
+        raise ScreenshotRefused("empty")
+    mime = sniff(data)
+    if mime is None:
+        raise ScreenshotRefused("not_an_image")
+    # Under both locks: two uploads at once cannot both pass the count (the session's), nor both
+    # pass the user's byte cap from two different sessions (the user's). Always in this order.
+    lock_user(db, session.user_id)
+    lock(db, session)
+    if sending(session):
+        raise ScreenshotRefused("sending")
+    if session.issue_url is not None:
+        raise ScreenshotRefused("already_sent")
+    if screenshot_count(db, session) >= SCREENSHOTS_MAX:
+        raise ScreenshotRefused("too_many")
+    if stored_screenshot_bytes(db, session.user_id) + len(data) > SCREENSHOT_USER_MAX_BYTES:
+        raise ScreenshotRefused("storage_full")
+    shot = DebugScreenshot(
+        session_id=session.id,
+        created_at=datetime.now(timezone.utc),
+        mime=mime,
+        size=len(data),
+        data=data,
+    )
+    db.add(shot)
+    db.flush()
+    return shot
+
+
+def remove_screenshot(db: Session, session: DebugSession, shot: DebugScreenshot) -> None:
+    """Delete one screenshot, under the lock. Refused while a send is under way or unfinished: a
+    delivery names the screenshots by their order, and removing one would renumber what it still
+    has to send. Once the issue has everything, this only drops OUR copy — the issue keeps its
+    own. The caller commits."""
+    lock(db, session)
+    if sending(session):
+        raise ScreenshotRefused("sending")
+    if unfinished(session):
+        raise ScreenshotRefused("already_sent")
+    db.delete(shot)
+    db.flush()
+
+
+def screenshots(db: Session, session: DebugSession) -> list[DebugScreenshot]:
+    """The session's screenshots, oldest first, WITHOUT their bytes loaded."""
+    return list(
+        db.scalars(
+            select(DebugScreenshot)
+            .where(DebugScreenshot.session_id == session.id)
+            .options(defer(DebugScreenshot.data))
+            .order_by(DebugScreenshot.id)
+        )
+    )
+
+
+# --- the evidence --------------------------------------------------------------------------
+# The browser's own log upload (`POST` here, every few seconds while recording) is how the evidence
+# arrives, not part of it: its server lines would fill the bundle with the recording's plumbing. The
+# browser leaves its copies out for the same reason (frontend lib/diagnostics `isOwnRequest`).
+INGEST_PATH = "/api/diagnostics/events"
+
+
+def _evidence(session: DebugSession):
+    upload_line = and_(
+        LogEvent.event == "http.request", LogEvent.attrs["path"].astext == INGEST_PATH
+    )
+    # `IS TRUE`, not the bare condition: for a row with no event or no attrs it is NULL, and
+    # `NOT NULL` would drop exactly the rows that are evidence.
+    return (LogEvent.debug_session_id == session.id, not_(upload_line.is_(True)))
+
+
+def bundle(
+    db: Session, session: DebugSession, *, drop_excluded: bool = False
+) -> tuple[list[LogEvent], int]:
+    """The session's log rows, browser and server interleaved in time, capped at BUNDLE_MAX — and
+    how many rows it has in all, so a cut bundle can say so. `drop_excluded` leaves out the rows
+    the user took out in the composer: what an export or an issue carries."""
+    where = list(_evidence(session))
+    excluded = (session.draft or {}).get("excluded") or [] if drop_excluded else []
+    if excluded:
+        where.append(LogEvent.id.not_in(excluded))
+    rows = list(
+        db.scalars(
+            select(LogEvent).where(*where).order_by(LogEvent.ts, LogEvent.id).limit(BUNDLE_MAX)
+        )
+    )
+    total = len(rows)
+    if total == BUNDLE_MAX:
+        total = db.scalar(select(func.count()).select_from(LogEvent).where(*where)) or total
+    return rows, total
+
+
+# --- housekeeping (the hourly log job) -----------------------------------------------------
+def sweep(db: Session) -> int:
+    """Stage closing every open session past its cap; returns how many."""
+    now = datetime.now(timezone.utc)
+    result = db.execute(
+        update(DebugSession)
+        .where(DebugSession.ended_at.is_(None), DebugSession.until <= now)
+        .values(ended_at=DebugSession.until, ended_reason=EndReason.EXPIRED.value)
+        .execution_options(synchronize_session=False)
+    )
+    return result.rowcount or 0
+
+
+def gc(db: Session, retention_days: int) -> int:
+    """Stage deleting sessions (and by cascade their screenshots) started before the log retention
+    window — the rows they would bundle are gone by then too. Returns how many."""
+    cutoff = datetime.now(timezone.utc) - timedelta(days=max(1, retention_days))
+    result = db.execute(delete(DebugSession).where(DebugSession.started_at < cutoff))
+    return result.rowcount or 0

backend/app/diagnostics.py

@@ -27,6 +27,9 @@ DiagnosticsLevel = Literal["INFO", "DEBUG", "TRACE"]
 LEVELS: tuple[str, ...] = get_args(DiagnosticsLevel)
 BASE: DiagnosticsLevel = "INFO"
 ELEVATION_HOURS = 24
+# How long a debug session records at most (E16, app/debugsession.py). Here, beside the other
+# consent window, because the start dialog's consent text states it and reads it from `state`.
+SESSION_MINUTES = 60
 
 
 def effective_level(user: User, now: datetime | None = None) -> DiagnosticsLevel:
@@ -47,6 +50,7 @@ def state(db: Session, user: User) -> dict:
         "level": level,
         "until": user.diagnostics_until.isoformat() if level != BASE else None,
         "retention_days": sysconfig.get_int(db, "log_retention_days"),
+        "session_minutes": SESSION_MINUTES,
     }
 
 

backend/app/discover/hero.py

@@ -81,7 +81,11 @@ def pick(
         return None
 
     def _comfort() -> dict | None:
-        for card in pins.playables(pins.shelf(db, user) if shelf is None else shelf):
+        if shelf is None:
+            own = pins.shelf(db, user, include_plex=rails.plex_available(db))
+        else:
+            own = shelf
+        for card in pins.playables(own):
             if cards.key(card) not in skip and fits(card["remaining_seconds"], budget):
                 return card
         return None

backend/app/discover/pins.py

@@ -8,14 +8,16 @@ second one.
 
 Every shelf card carries a resolved `next`: the thing that actually plays when you click the tile —
 a show's in-progress-or-next episode, a channel's newest unwatched video, a playlist's first
-unwatched item. It costs a query per non-leaf pin, which is affordable precisely because this shelf is
-short and hand-curated, and it buys the property the whole surface exists for: one click, no
-intermediate page, no second decision.
+unwatched item. That buys the property the whole surface exists for: one click, no intermediate page,
+no second decision. Channels and playlists are resolved for the whole shelf at once (`_Batch`), so the
+cost does not grow a query or two per pin.
 
 Domain module, so nothing here raises HTTP. `resolve_ref` returns None for "no such thing, or not
 yours" and the route turns that into its 404 — core never imports routes.
 """
 
+from dataclasses import dataclass, field
+
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
@@ -73,6 +75,44 @@ def resolve_ref(db: Session, user: User, kind: str, ref: str) -> tuple[str, obje
     return (col, pl.id) if pl is not None and pl.user_id == user.id else None
 
 
+def reorder(db: Session, user: User, ids: list[int]) -> None:
+    """Put the listed pins in the listed order, WITHIN the slots they already hold.
+
+    The client sends the order it can SEE, which is not always the whole shelf: with Plex off the Home
+    rail hides the Plex pins, and a stale tab may not know a pin added elsewhere. Numbering only the
+    listed ids 0..n-1 collided with every pin left out — two tiles on one position, and the hidden
+    ones jumped about when they came back. So the pins left out keep their slots, and the listed ones
+    are dealt into the slots the listed set occupies. Ids that are not this user's, or repeated, are
+    ignored rather than failing a stale replay wholesale. Flushes; the route commits."""
+    # Locked: the rows it leaves alone are part of the answer too. Two overlapping reorders each
+    # skipped the rows that already matched in their own snapshot and interleaved into two pins on
+    # one slot; the second now waits and deals from the first one's result. Locked in id order and
+    # sorted HERE: with `ORDER BY position … FOR UPDATE` Postgres sorts before it locks, so the one
+    # that waited got the fresh rows in its stale order and dealt the pins it left out back to their
+    # old slots — and one global lock order means two reorders cannot deadlock.
+    locked = db.execute(
+        select(ComfortPin)
+        .where(ComfortPin.user_id == user.id)
+        .order_by(ComfortPin.id)
+        .with_for_update()
+        .execution_options(populate_existing=True)
+    ).scalars()
+    current = sorted(locked, key=lambda p: (p.position, p.id))
+    owned = {p.id for p in current}
+    listed: list[int] = []
+    for i in ids:
+        if i in owned and i not in listed:
+            listed.append(i)
+    chosen = set(listed)
+    queue = iter(listed)
+    order = [next(queue) if p.id in chosen else p.id for p in current]
+    by_id = {p.id: p for p in current}
+    for position, pin_id in enumerate(order):
+        if by_id[pin_id].position != position:
+            by_id[pin_id].position = position
+    db.flush()
+
+
 def list_pins(db: Session, user: User) -> list[ComfortPin]:
     return list(
         db.execute(
@@ -103,7 +143,34 @@ def next_position(db: Session, user: User) -> int:
     )
 
 
-def _shelf_card(db: Session, user: User, pin: ComfortPin) -> dict | None:
+@dataclass
+class _Batch:
+    """What the shelf resolves for every pinned channel and playlist in one go."""
+
+    channels: dict[str, Channel] = field(default_factory=dict)
+    channel_summary: dict[str, tuple[int, dict | None]] = field(default_factory=dict)
+    playlists: dict[int, Playlist] = field(default_factory=dict)
+    playlist_summary: dict[int, tuple[int, dict | None]] = field(default_factory=dict)
+
+    @classmethod
+    def load(cls, db: Session, user: User, pins: list[ComfortPin]) -> "_Batch":
+        ch_ids = [p.channel_id for p in pins if p.channel_id is not None]
+        pl_ids = [p.playlist_id for p in pins if p.playlist_id is not None]
+        b = cls()
+        if ch_ids:
+            b.channels = {
+                c.id: c for c in db.scalars(select(Channel).where(Channel.id.in_(ch_ids)))
+            }
+            b.channel_summary = queries.channels_summary(db, user, ch_ids)
+        if pl_ids:
+            b.playlists = {
+                p.id: p for p in db.scalars(select(Playlist).where(Playlist.id.in_(pl_ids)))
+            }
+            b.playlist_summary = queries.playlists_summary(db, user, pl_ids)
+        return b
+
+
+def _shelf_card(db: Session, user: User, pin: ComfortPin, batch: _Batch) -> dict | None:
     """One pin as a unified card with its resolved `next`. None when the pinned row has gone (the FK
     cascade removes the pin itself, so this is only the window between a delete and a refetch)."""
     card: dict | None = None
@@ -117,11 +184,11 @@ def _shelf_card(db: Session, user: User, pin: ComfortPin) -> dict | None:
         nxt = dict(card)  # a video plays itself
 
     elif pin.channel_id is not None:
-        ch = db.get(Channel, pin.channel_id)
+        ch = batch.channels.get(pin.channel_id)
         if ch is None:
             return None
-        card = cards.from_channel(ch, queries.channel_unwatched_count(db, user, ch.id))
-        row = queries.channel_next_video(db, user, ch.id)
+        count, row = batch.channel_summary.get(ch.id, (0, None))
+        card = cards.from_channel(ch, count)
         nxt = cards.from_video(row) if row else None
 
     elif pin.plex_item_id is not None:
@@ -142,10 +209,10 @@ def _shelf_card(db: Session, user: User, pin: ComfortPin) -> dict | None:
         nxt = cards.from_plex(ep) if ep else None
 
     elif pin.playlist_id is not None:
-        pl = db.get(Playlist, pin.playlist_id)
+        pl = batch.playlists.get(pin.playlist_id)
         if pl is None:
             return None
-        count, row = queries.playlist_summary(db, user, pl.id)
+        count, row = batch.playlist_summary.get(pl.id, (0, None))
         card = cards.from_playlist(pl, count, row.get("thumbnail_url") if row else None)
         nxt = cards.from_video(row) if row else None
 
@@ -159,11 +226,24 @@ def _shelf_card(db: Session, user: User, pin: ComfortPin) -> dict | None:
     return card
 
 
-def shelf(db: Session, user: User) -> list[dict]:
-    """The whole shelf, in the user's own order."""
+_PLEX_COLUMNS = ("plex_item_id", "plex_show_id")
+
+
+def shelf(db: Session, user: User, *, include_plex: bool = True) -> list[dict]:
+    """The whole shelf, in the user's own order.
+
+    `include_plex=False` is the Home surface with the deployment's Plex toggle off (the owner's call,
+    2026-09-19): the rails beside it go YouTube-only, and a Plex tile there would offer a Play that
+    lands on a gated module. The pins themselves are kept — the pin menus still read the full shelf
+    (`GET /pins`), and switching Plex back on brings the tiles back in their old slots
+    (`reorder` keeps a hidden pin's place)."""
     out = []
-    for pin in list_pins(db, user):
-        card = _shelf_card(db, user, pin)
+    pins = list_pins(db, user)
+    if not include_plex:
+        pins = [p for p in pins if all(getattr(p, c) is None for c in _PLEX_COLUMNS)]
+    batch = _Batch.load(db, user, pins)
+    for pin in pins:
+        card = _shelf_card(db, user, pin, batch)
         if card is not None:
             out.append(card)
     return out
@@ -171,5 +251,17 @@ def shelf(db: Session, user: User) -> list[dict]:
 
 def playables(shelf_cards: list[dict]) -> list[dict]:
     """The `next` of every shelf entry that has one — what the hero may draw from. A pinned channel
-    with nothing unwatched left, or an empty playlist, simply is not an answer right now."""
-    return [c["next"] for c in shelf_cards if c.get("next")]
+    with nothing unwatched left, or an empty playlist, simply is not an answer right now.
+
+    Each carries `pinned_from`: the pin it was resolved from. A show's next EPISODE is not itself
+    pinned, so without it the hero's menu looked the episode up, missed, and offered "Pin" under a
+    kicker that says "From your shelf" — and taking it inserted a second pin. With it, the hero's
+    pin row acts on the shelf entry the card came from (the owner's call, 2026-09-19: "Unpin")."""
+    return [
+        {
+            **c["next"],
+            "pinned_from": {k: c[k] for k in ("source", "kind", "id", "title")},
+        }
+        for c in shelf_cards
+        if c.get("next")
+    ]

backend/app/discover/queries.py

@@ -43,8 +43,9 @@ from app.plex import rollup
 from app.plex.cards import leaf_card, movie_card, show_card
 from app.plex.query import apply_show_state_filter, content_libs
 
-# How many rows a single rail may carry. Matches `routes/plex/discover.py`'s RAIL_LIMIT on purpose —
-# the two surfaces should feel like the same app, and a rail is a rail.
+# How many rows a single rail may carry — Home's rails and the Plex module's Discover rails alike
+# (`routes/plex/discover.py` imports it): the two surfaces should feel like the same app, and a rail
+# is a rail. One definition, because a comment was all that held two copies in step.
 RAIL_LIMIT = 20
 
 # The feed parameters a Home rail runs with. Spelled out rather than borrowed from the route's
@@ -129,18 +130,6 @@ def yt_surprise(db: Session, user: User, budget: str, seed: int, limit: int) ->
     return [r for r in out if not r["position_seconds"]][:limit]
 
 
-def channel_next_video(db: Session, user: User, channel_id: str) -> dict | None:
-    """The newest unwatched video of a pinned channel — what "put on that channel" resolves to."""
-    # `library_source="all"`: a pinned channel means the whole channel, including videos that only
-    # ever arrived through a search. The feed's "organic" default is a feed-scoping choice, not a
-    # statement about what belongs to a channel.
-    params = dict(_FEED_BASE, channel_ids=[channel_id], scope="all", library_source="all")
-    query, rank_expr = filtered_query(db, user, **params)
-    keys = sort_keys("newest", 0, rank_expr)
-    row = db.execute(query.order_by(*order_by(keys)).limit(1)).first()
-    return serialize(row) if row is not None else None
-
-
 def yt_video_row(db: Session, user: User, video_id: str) -> dict | None:
     """One video as a feed row, with this user's watch state.
 
@@ -158,31 +147,55 @@ def yt_video_row(db: Session, user: User, video_id: str) -> dict | None:
     return serialize(row) if row is not None else None
 
 
-def channel_unwatched_count(db: Session, user: User, channel_id: str) -> int:
-    """How many unwatched videos a pinned channel is holding — the tile's only honest promise, since a
-    channel has no runtime of its own."""
-    params = dict(_FEED_BASE, channel_ids=[channel_id], scope="all", library_source="all")
-    query, _ = filtered_query(db, user, **params)
-    return int(db.execute(select(func.count()).select_from(query.subquery())).scalar() or 0)
+def channels_summary(
+    db: Session, user: User, channel_ids: list[str]
+) -> dict[str, tuple[int, dict | None]]:
+    """For each pinned channel: (unwatched count, its newest unwatched video) — the tile's only honest
+    promise, since a channel has no runtime of its own, and what "put on that channel" resolves to.
+
+    ONE query for the whole shelf, not two per channel: the count and the first row per channel are
+    window functions over the same filtered set. `library_source="all"`: a pinned channel means the
+    whole channel, including videos that only ever arrived through a search — the feed's "organic"
+    default is a feed-scoping choice, not a statement about what belongs to a channel."""
+    if not channel_ids:
+        return {}
+    params = dict(_FEED_BASE, channel_ids=list(channel_ids), scope="all", library_source="all")
+    query, rank_expr = filtered_query(db, user, **params)
+    newest = order_by(sort_keys("newest", 0, rank_expr))
+    per_channel = {"partition_by": Video.channel_id}
+    sub = query.add_columns(
+        func.row_number().over(**per_channel, order_by=newest).label("_rn"),
+        func.count().over(**per_channel).label("_total"),
+    ).subquery()
+    rows = db.execute(select(sub).where(sub.c._rn == 1)).all()
+    return {r.channel_id: (int(r._total), serialize(r)) for r in rows}
 
 
-def playlist_summary(db: Session, user: User, playlist_id: int) -> tuple[int, dict | None]:
-    """(item count, the row to play next) for a pinned playlist — its first not-yet-watched item, or
-    its first item once the whole list is watched. The same row doubles as the tile's artwork, so a
-    shelf of playlists is scannable instead of a row of blank boxes."""
+def playlists_summary(
+    db: Session, user: User, playlist_ids: list[int]
+) -> dict[int, tuple[int, dict | None]]:
+    """For each pinned playlist: (item count, the row to play next) — its first not-yet-watched item,
+    or its first item once the whole list is watched. The same row doubles as the tile's artwork, so
+    a shelf of playlists is scannable instead of a row of blank boxes. One query for the whole shelf."""
+    if not playlist_ids:
+        return {}
     st = aliased(VideoState)
     rows = db.execute(
-        select(*feed_columns(user, st), PlaylistItem.position)
+        select(*feed_columns(user, st), PlaylistItem.playlist_id.label("_playlist"))
         .join(PlaylistItem, PlaylistItem.video_id == Video.id)
         .join(Channel, Channel.id == Video.channel_id)
         .outerjoin(st, and_(st.video_id == Video.id, st.user_id == user.id))
-        .where(PlaylistItem.playlist_id == playlist_id)
-        .order_by(PlaylistItem.position.asc())
+        .where(PlaylistItem.playlist_id.in_(playlist_ids))
+        .order_by(PlaylistItem.playlist_id, PlaylistItem.position.asc())
     ).all()
-    if not rows:
-        return 0, None
-    nxt = next((r for r in rows if (r.status or "new") not in ("watched", "hidden")), rows[0])
-    return len(rows), serialize(nxt)
+    grouped: dict[int, list] = {}
+    for r in rows:
+        grouped.setdefault(r._playlist, []).append(r)
+    out: dict[int, tuple[int, dict | None]] = {}
+    for pid, items in grouped.items():
+        nxt = next((r for r in items if (r.status or "new") not in ("watched", "hidden")), items[0])
+        out[pid] = (len(items), serialize(nxt))
+    return out
 
 
 # ── Plex ──────────────────────────────────────────────────────────────────────────────────────────

backend/app/feedquery.py

@@ -30,7 +30,7 @@ from app.models import (
     Video,
     VideoState,
 )
-from app.utils import iso, to_tsquery_str
+from app.utils import iso, like_escape, to_tsquery_str
 
 
 def _channel_url(channel_id: str, handle: str | None) -> str:
@@ -272,8 +272,9 @@ def filtered_query(
         # `unaccent(channels.title) ILIKE '%q%'` straight into the per-video predicate defeated the
         # search_vector GIN — the planner detoasted every non-matching tsvector to test the `@@`
         # (~2.6s/search on the prod-sized set); channel_id.in_(...) keeps the GIN as a BitmapOr branch
-        # (PERF-12). Empty match -> false() so the OR collapses to the text match alone.
-        like = func.unaccent(f"%{q}%")
+        # (PERF-12). Empty match -> false() so the OR collapses to the text match alone. The query
+        # is a literal inside the pattern: `_` in `my_channel` is not a wildcard.
+        like = func.unaccent(f"%{like_escape(q)}%")
         matching_channel_ids = (
             db.execute(select(Channel.id).where(func.unaccent(Channel.title).ilike(like)))
             .scalars()

backend/app/issues/__init__.py

@@ -0,0 +1,3 @@
+"""Bug reports built from debug sessions (E16): the files an issue carries, and where they go —
+downloaded as a zip, or (S4) sent to a Gitea issue tracker. The session itself — what is recorded
+and tagged — is the core module `app/debugsession.py`."""

backend/app/issues/bundle.py

@@ -0,0 +1,79 @@
+"""What an issue from a debug session carries, as files — one definition for the zip export and the
+Gitea upload, so the two cannot drift apart.
+
+  * `issue.md` — the title and the body the user wrote and reviewed in the composer (rendered there,
+    in their language; the server does not rewrite it);
+  * `client.log` / `server.log` — the session's evidence (`debugsession.bundle`) minus the rows the
+    user took out, one JSON object per line, browser rows and server rows apart. `.log`, not
+    `.jsonl`: Gitea refuses that extension (measured, plans/e16 S0);
+  * the screenshots, in the order they were taken.
+
+Every row is already redacted twice (at capture, and again when stored), and nothing here adds a
+field the review list did not show.
+"""
+
+import io
+import json
+import zipfile
+from dataclasses import dataclass
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app import debugsession, logsink
+from app.models import DebugScreenshot, DebugSession
+
+
+@dataclass(frozen=True)
+class IssueFile:
+    name: str
+    data: bytes
+    mime: str
+
+
+def title_of(session: DebugSession) -> str:
+    # Not a sentence of ours: the composer always saves a title in the user's language, and a
+    # session exported before it ever saved is named by its date alone, in no language at all.
+    title = ((session.draft or {}).get("title") or "").strip()
+    return title or f"{session.started_at:%Y-%m-%d %H:%M} · {session.id}"
+
+
+def body_of(session: DebugSession) -> str:
+    return ((session.draft or {}).get("body") or "").strip()
+
+
+def _lines(rows) -> bytes:
+    return "".join(
+        json.dumps(logsink.serialize(r), ensure_ascii=False, default=str) + "\n" for r in rows
+    ).encode()
+
+
+def files(db: Session, session: DebugSession) -> list[IssueFile]:
+    """The session's issue as files: the text, the two logs, the screenshots."""
+    rows, _ = debugsession.bundle(db, session, drop_excluded=True)
+    text = f"# {title_of(session)}\n\n{body_of(session)}\n"
+    out = [
+        IssueFile("issue.md", text.encode(), "text/markdown"),
+        IssueFile("client.log", _lines(r for r in rows if r.source == "web"), "text/plain"),
+        IssueFile("server.log", _lines(r for r in rows if r.source != "web"), "text/plain"),
+    ]
+    shots = db.scalars(
+        select(DebugScreenshot)
+        .where(DebugScreenshot.session_id == session.id)
+        .order_by(DebugScreenshot.id)
+    )
+    for n, shot in enumerate(shots, start=1):
+        ext = debugsession.IMAGE_TYPES[shot.mime]
+        name = f"{debugsession.SCREENSHOT_PREFIX}{n}.{ext}"
+        out.append(IssueFile(name, shot.data, shot.mime))
+    return out
+
+
+def zipped(items: list[IssueFile]) -> bytes:
+    buf = io.BytesIO()
+    with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as z:
+        for item in items:
+            # The images are compressed already: deflating them again costs time and wins nothing.
+            method = zipfile.ZIP_STORED if item.mime.startswith("image/") else zipfile.ZIP_DEFLATED
+            z.writestr(item.name, item.data, compress_type=method)
+    return buf.getvalue()

backend/app/issues/gitea.py

@@ -0,0 +1,288 @@
+"""The Gitea issue tracker a debug session's issue goes to (E16 S4) — measured against Gitea 1.27.1
+before a line of this was written (plans/e16-debug-issue.md, S0).
+
+Configured by an admin (sysconfig `issues_gitea_url` / `_repo` / `_token`, the token encrypted at
+rest). The repository must be PRIVATE: an issue carries its reporter's log — page titles, filter
+values, at Teljes (TRACE) what they typed into search — and a public repository would publish it. That is
+checked on every send, not only in the admin's "test connection", because a repository can be made
+public after the fact.
+
+What an issue is made of comes from `bundle.files` (the same files the zip export carries). Sending
+is three kinds of call, measured:
+  * `POST /repos/{repo}/issues` — the title and the body the user wrote;
+  * `POST /repos/{repo}/issues/{n}/assets?name=…` — ONE file per request (field `attachment`);
+  * `PATCH /repos/{repo}/issues/{n}` — the body again, with the screenshots shown inline once their
+    links exist.
+A private repository's attachment answers 404 to a browser not signed in to Gitea, which is why the
+composer's own preview shows our copies, never these links.
+
+Delivery keeps its progress in the session's draft (`delivery`: the issue number, the files still to
+upload, the links of those uploaded, whether the body shows the screenshots yet), so a failure
+half-way keeps the issue that exists and a retry does only what is missing — never a second issue.
+Every step is checkpointed (the caller's `db.commit`), so what did happen is kept whatever fails
+next — and the first checkpoint comes before the first call, with the tracker's settings read ABOVE
+it, so neither a row lock nor a read snapshot nor a pooled connection is held across the calls. The
+caller claims the session for the send first (`debugsession.claim_send`) and passes the claim's
+token in, which is what keeps a second send, an autosave or a screenshot out of the way; the claim
+is renewed by every progress report, and a report whose claim is gone raises rather than writing
+over the send that took it. `debugsession.not_uploaded` / `images_pending` read that progress.
+"""
+
+from collections.abc import Callable, Iterator
+from contextlib import contextmanager
+from typing import Any, Literal
+
+import httpx
+from sqlalchemy.orm import Session
+
+from app import debugsession, logs, sysconfig
+from app.issues import bundle
+from app.models import DebugSession
+
+log = logs.get_logger(__name__)
+
+TIMEOUT_SECONDS = 20.0
+
+Reason = Literal[
+    "not_configured",  # url, repository or token missing
+    "unreachable",  # no answer, or a 5xx
+    "bad_token",  # 401/403: the token is wrong or lacks write:issue / read:repository
+    "repo_not_found",  # 404 on the repository
+    "public_repo",  # the repository is public — an issue would publish the reporter's log
+    "issues_disabled",  # the repository has its issue tracker switched off
+    "rejected",  # any other 4xx (a file type the instance does not allow, …), or an answer that is
+    # not the API's (a redirect — an http:// address behind https —, a page that is not JSON)
+]
+
+
+class GiteaError(Exception):
+    def __init__(self, reason: Reason) -> None:
+        super().__init__(reason)
+        self.reason: Reason = reason
+
+
+def _settings(db: Session) -> tuple[str, str, str]:
+    return (
+        sysconfig.get_str(db, "issues_gitea_url").strip().rstrip("/"),
+        sysconfig.get_str(db, "issues_gitea_repo").strip().strip("/"),
+        sysconfig.get_str(db, "issues_gitea_token").strip(),
+    )
+
+
+def target(db: Session) -> dict | None:
+    """Where a report goes, for the composer to say so — the repository — or None when no tracker is
+    configured (the report can then only be downloaded)."""
+    url, repo, token = _settings(db)
+    return {"repo": repo} if url and repo and token else None
+
+
+@contextmanager
+def _client(settings: tuple[str, str, str]) -> Iterator[tuple[httpx.Client, str]]:
+    # Takes the settings already read, not the session: reading them HERE opened a transaction one
+    # line after `deliver` had ended one, and held it across the calls below (deep-review round 4).
+    url, repo, token = settings
+    if not (url and repo and token):
+        raise GiteaError("not_configured")
+    with httpx.Client(
+        base_url=f"{url}/api/v1",
+        headers={"Authorization": f"token {token}", "Accept": "application/json"},
+        timeout=TIMEOUT_SECONDS,
+    ) as client:
+        yield client, repo
+
+
+def _call(client: httpx.Client, method: str, path: str, **kwargs) -> httpx.Response:
+    try:
+        r = client.request(method, path, **kwargs)
+    except httpx.HTTPError as exc:
+        log.warning(
+            "the issue tracker did not answer",
+            extra=logs.event("issues.gitea.unreachable", path=path, error=type(exc).__name__),
+        )
+        raise GiteaError("unreachable") from None
+    if r.status_code < 300:
+        return r
+    # The status only: Gitea's message can quote back what was sent — the user's own title.
+    log.warning(
+        "the issue tracker refused a call",
+        extra=logs.event("issues.gitea.refused", path=path, status=r.status_code),
+    )
+    if r.status_code in (401, 403):
+        raise GiteaError("bad_token")
+    if r.status_code == 404:
+        raise GiteaError("repo_not_found")
+    if r.status_code >= 500:
+        raise GiteaError("unreachable")
+    raise GiteaError("rejected")
+
+
+def _json(r: httpx.Response, *keys: str) -> dict[str, Any]:
+    """The answer as the API's JSON, holding `keys` — anything else is refused, not a crash, so a
+    step after the issue was created cannot take down the request that holds its record.
+
+    The CREATE call is the one place this cannot keep that record: its answer IS the record. An
+    answer it cannot read there leaves the session unsent, and a retry opens another issue — the
+    price of not being able to tell a refused create from an unreadable one."""
+    try:
+        data = r.json()
+    # silent-ok: not JSON is one of the answers refused (and logged) just below.
+    except ValueError:
+        data = None
+    if not isinstance(data, dict) or any(k not in data for k in keys):
+        log.warning(
+            "the issue tracker answered something that is not its API",
+            extra=logs.event("issues.gitea.unexpected", status=r.status_code),
+        )
+        raise GiteaError("rejected")
+    return data
+
+
+def _private_repo(client: httpx.Client, repo: str) -> dict:
+    data = _json(_call(client, "GET", f"/repos/{repo}"))
+    if not data.get("private"):
+        raise GiteaError("public_repo")
+    if not data.get("has_issues"):
+        raise GiteaError("issues_disabled")
+    return data
+
+
+def check(db: Session) -> dict:
+    """The admin's "test connection": the repository answers, is private and takes issues."""
+    with _client(_settings(db)) as (client, repo):
+        data = _private_repo(client, repo)
+    return {"repo": data.get("full_name") or repo, "url": data.get("html_url")}
+
+
+def preview(db: Session, text: str) -> str:
+    """The body as Gitea itself will render it (its markdown flavour, its sanitiser).
+
+    **No `Context`, deliberately — a repository context here does not fail the call, it kills the
+    tracker.** With one, Gitea's post-processor turns every hex-shaped word into a commit link, and
+    on the API's render path the commit checker it asks is nil: the whole Gitea process segfaults
+    and restarts, taking the git server (and, here, the container registry) down with it. Every
+    report carries hex — a tab id, a request id — so this was not an edge case but the only case.
+    Measured on throwaway instances (2026-09-20): `{"Mode": "gfm", "Context": "<repo>"}` with
+    `5645b1c0ae01` in the text crashes 1.26.4 and 1.27.1 and is fixed in 1.27.3 — but a self-hoster
+    runs whatever version they run, so the payload stays safe here rather than relying on theirs.
+    Dropping `Context` is not a downgrade of the preview: measured against the same body, the HTML
+    keeps its tables, its task lists and its highlighted code blocks. It only stops resolving
+    repo-relative links (a hash, a `#123`), which the issue page itself still resolves.
+    """
+    with _client(_settings(db)) as (client, _repo):
+        r = _call(client, "POST", "/markdown", json={"Text": text, "Mode": "gfm"})
+    return r.text
+
+
+def deliver(
+    db: Session,
+    session: DebugSession,
+    *,
+    token: str,
+    checkpoint: Callable[[], None],
+    before_create: Callable[[], None] | None = None,
+    on_created: Callable[[], None] | None = None,
+) -> str:
+    """Send the session's issue, or finish sending it; returns its URL.
+
+    `token` is the caller's claim on this session (`debugsession.claim_send`). Every progress report
+    renews it and checks the row still holds it, so a send that outlived its lease stops here rather
+    than writing over the one that took over (`debugsession.SendClaimLost`).
+
+    `checkpoint` persists what has happened so far and is called after every step (the caller's
+    commit — this module does not decide when a transaction ends). `before_create` runs right before
+    the tracker is asked to open a NEW issue, after the checks that can refuse it without asking,
+    and may raise to stop it; `on_created` runs right after one was opened, in time to be committed
+    by the SAME checkpoint that first writes `issue_url` — anything the caller must not be able to
+    lose separately from the link belongs there.
+    """
+    state = debugsession.delivery(session)
+    files = bundle.files(db, session)
+    attachments = [f for f in files if f.name != "issue.md"]
+    settings = _settings(db)
+    # Reading the bundle and the tracker's settings opened a transaction; end it before the first
+    # call, so nothing holds a snapshot (and an idle connection) across minutes of tracker I/O.
+    # The settings are read HERE and handed to `_client`, not read inside it: reading them there
+    # was a SELECT one line after this commit, which reopened the transaction and held it — idle,
+    # with its snapshot pinned — across the repository check and the create (deep-review round 4
+    # measured it in pg_stat_activity). A comment saying otherwise sat right here.
+    checkpoint()
+    with _client(settings) as (client, repo):
+        _private_repo(client, repo)
+        if "number" not in state:
+            if before_create is not None:
+                before_create()
+            created = _json(
+                _call(
+                    client,
+                    "POST",
+                    f"/repos/{repo}/issues",
+                    json={"title": bundle.title_of(session), "body": bundle.body_of(session)},
+                ),
+                "number",
+                "html_url",
+            )
+            # Built ON the state read at the start so nothing already in it is dropped. The claim
+            # is NOT among those things, whatever this comment used to say: `set_delivery` strips
+            # any `sending` passed to it and stamps the row's own from `token` (round 4 — removing
+            # the spread left the whole suite green, because the claim never travelled here).
+            state = {
+                **state,
+                "number": created["number"],
+                "pending": [f.name for f in attachments],
+                "links": {},
+            }
+            session.issue_url = created["html_url"]
+            try:
+                debugsession.set_delivery(db, session, state, token)
+            except debugsession.SendClaimLost:
+                # The one step where losing the claim costs something irreversible: the issue is
+                # already open on the tracker and this is what would have recorded its link. We
+                # still must not write — another send owns the row and is opening its own issue —
+                # so say which issue was left behind, because nothing else will.
+                # noqa TRY400: the traceback is one SendClaimLost carrying the session id and
+                # nothing else; the issue number below is the whole news.
+                log.error(  # noqa: TRY400
+                    "an issue was created by a send that had already lost its claim",
+                    extra=logs.event(
+                        "issues.gitea.orphaned",
+                        number=created["number"],
+                        session_id=session.id,
+                    ),
+                )
+                raise
+            if on_created is not None:
+                on_created()
+            checkpoint()
+            log.info(
+                "issue created",
+                extra=logs.event("issues.gitea.created", number=created["number"]),
+            )
+        number = state["number"]
+        for item in attachments:
+            if item.name not in state["pending"]:
+                continue
+            asset = _json(
+                _call(
+                    client,
+                    "POST",
+                    f"/repos/{repo}/issues/{number}/assets",
+                    params={"name": item.name},
+                    files={"attachment": (item.name, item.data, item.mime)},
+                ),
+                "browser_download_url",
+            )
+            state = {
+                **state,
+                "pending": [n for n in state["pending"] if n != item.name],
+                "links": {**state["links"], item.name: asset["browser_download_url"]},
+            }
+            debugsession.set_delivery(db, session, state, token)
+            checkpoint()
+        shots = [n for n in state["links"] if n.startswith(debugsession.SCREENSHOT_PREFIX)]
+        if shots and not state.get("images_shown"):
+            images = "\n".join(f"![{n}]({state['links'][n]})" for n in sorted(shots))
+            body = f"{bundle.body_of(session)}\n\n---\n\n{images}"
+            _call(client, "PATCH", f"/repos/{repo}/issues/{number}", json={"body": body})
+            debugsession.set_delivery(db, session, {**state, "images_shown": True}, token)
+            checkpoint()
+    return session.issue_url or ""

backend/app/logs.py

@@ -100,12 +100,14 @@ class _RequestScope:
     request; every copied context shares the same object, so what the dependency writes is seen by
     the handler and by the request line itself."""
 
-    __slots__ = ("user_id", "level")
+    __slots__ = ("user_id", "level", "debug_session_id")
 
     def __init__(self) -> None:
         self.user_id: int | None = None
         # The user's consented diagnostics level as a logging number; None at the base level.
         self.level: int | None = None
+        # The user's own open debug session this request named (E16), else None.
+        self.debug_session_id: str | None = None
 
 
 _scope: contextvars.ContextVar[_RequestScope | None] = contextvars.ContextVar(
@@ -113,11 +115,23 @@ _scope: contextvars.ContextVar[_RequestScope | None] = contextvars.ContextVar(
 )
 
 
-def set_user(user_id: int | None, level: str = "INFO", until: datetime | None = None) -> None:
+def set_user(
+    user_id: int | None,
+    level: str = "INFO",
+    until: datetime | None = None,
+    debug_session: str | None = None,
+) -> None:
     """Attribute the rest of this request's log lines to `user_id`, and log them at the user's
     consented diagnostics `level` until `until` (E22 S5; "INFO" = no elevation). Called from the
     auth dependency — the one place the session is actually resolved into an account — rather than
-    from the request middleware, which runs OUTSIDE the session middleware."""
+    from the request middleware, which runs OUTSIDE the session middleware.
+
+    `debug_session` tags every line with the user's open debug session (E16). The caller has
+    already checked it is theirs and open; a session's level arrives here as `level`/`until`.
+
+    The root logger's floor is tracked per elevation: a request without the session's header (an
+    `<img>`, a `<video>` — the browser sends those itself) carries only the user's own level, and
+    must not lower the floor a concurrent request of the session still needs."""
     _user_id.set(user_id)
     scope = _scope.get()
     if scope is None:  # outside log_requests (a script, a unit test): this context only
@@ -125,9 +139,11 @@ def set_user(user_id: int | None, level: str = "INFO", until: datetime | None =
         _scope.set(scope)
     elevated = level != "INFO" and until is not None and until > datetime.now(timezone.utc)
     scope.user_id = user_id
+    scope.debug_session_id = debug_session
     scope.level = resolve_level(level) if elevated else None
     if user_id is not None:
-        _track_elevation(user_id, scope.level, until)
+        key = user_id if debug_session is None else (user_id, debug_session)
+        _track_elevation(key, scope.level, until)
 
 
 def set_job(job_id: int | None) -> None:
@@ -328,6 +344,12 @@ class ContextFilter(logging.Filter):
         scope = _scope.get()
         if scope is not None and scope.user_id is not None and not hasattr(record, "user_id"):
             record.user_id = scope.user_id
+        if (
+            scope is not None
+            and scope.debug_session_id is not None
+            and not hasattr(record, "debug_session_id")
+        ):
+            record.debug_session_id = scope.debug_session_id
         return True
 
 
@@ -545,18 +567,21 @@ def current_level() -> str:
 # The base level (`LOG_LEVEL`, then the admin knob). NOTSET until configure_logging runs — a unit
 # test, a script — so the gate lets everything through there, as it did before the gate existed.
 _base_level = logging.NOTSET
-# user id → (level number, expiry) for every elevation this process has seen and not yet expired.
-_elevations: dict[int, tuple[int, datetime]] = {}
+# → (level number, expiry) for every elevation this process has seen and not yet expired: a user's
+# own, by user id, and a debug session's (E16), by (user id, session id) — its requests alone carry
+# its level, so it is tracked apart from the user's own requests.
+_ElevationKey = int | tuple[int, str]
+_elevations: dict[_ElevationKey, tuple[int, datetime]] = {}
 _elevations_lock = threading.Lock()
 _root_applied: int | None = None
 
 
-def _track_elevation(user_id: int, level: int | None, until: datetime | None) -> None:
+def _track_elevation(key: _ElevationKey, level: int | None, until: datetime | None) -> None:
     with _elevations_lock:
         if level is None or until is None:
-            _elevations.pop(user_id, None)
+            _elevations.pop(key, None)
         else:
-            _elevations[user_id] = (level, until)
+            _elevations[key] = (level, until)
         active = bool(_elevations)
     if active or _root_applied != _base_level:
         _apply_root_level()
@@ -573,8 +598,8 @@ def _apply_root_level(force: bool = False) -> None:
     # different answer would otherwise apply them in either order, and the older one could win —
     # the root back at the base while an elevation is still active.
     with _elevations_lock:
-        for user_id in [u for u, (_, until) in _elevations.items() if until <= now]:
-            del _elevations[user_id]
+        for key in [k for k, (_, until) in _elevations.items() if until <= now]:
+            del _elevations[key]
         lowest = min([_base_level, *(lvl for lvl, _ in _elevations.values())])
         if force or lowest != _root_applied:
             logging.getLogger().setLevel(lowest)
@@ -611,13 +636,24 @@ def forget_user(user_id: int) -> None:
             del _erased[stale]
         _erased[user_id] = now
     with _elevations_lock:
-        _elevations.pop(user_id, None)
+        for key in [
+            k for k in _elevations if k == user_id or (isinstance(k, tuple) and k[0] == user_id)
+        ]:
+            del _elevations[key]
     # That pop can have removed the lowest elevation, and the root level is the lowest of the base
     # and every unexpired one. Recomputed here rather than left to whichever later request happens
     # to call `_track_elevation` — the invariant `_apply_root_level` documents holds at every pop.
     _apply_root_level()
 
 
+def end_session_elevation(session_id: str) -> None:
+    """A debug session was stopped: its elevation ends now, not at its cap."""
+    with _elevations_lock:
+        for key in [k for k in _elevations if isinstance(k, tuple) and k[1] == session_id]:
+            del _elevations[key]
+    _apply_root_level()
+
+
 def is_erased(user_id: int | None) -> bool:
     if user_id is None:
         return False
@@ -638,9 +674,32 @@ def current_source() -> str:
 _REQUEST_ID_RE = re.compile(r"^[A-Za-z0-9._-]{8,64}$")
 
 # Paths whose success is logged at DEBUG rather than INFO: the container healthcheck runs every 15s
-# (5.7k lines/day saying nothing) and hashed static assets are served by the hundred per page load.
-# A FAILURE on either still logs at WARNING/ERROR — this lowers the floor, it does not hide.
-_QUIET_PREFIXES = ("/healthz", "/assets/", "/static/")
+# (5.7k lines/day saying nothing), hashed static assets are served by the hundred per page load, and
+# the admin log console reads the stored log — its live tail every few seconds, so at INFO the log
+# would fill with the console watching itself. A FAILURE on any of them still logs at WARNING/ERROR
+# — this lowers the floor, it does not hide.
+_QUIET_PREFIXES = ("/healthz", "/assets/", "/static/", "/api/admin/logs")
+
+# The reads the frontend POLLS (a `useLiveQuery`, the `me` heartbeat, the sync status, the subtitle
+# progress), by route template, GET only — logged at DEBUG like the prefixes above. One open tab asked
+# for the two unread counts, `/api/me` and the download index every 30 s, and at INFO those were ~95%
+# of the stored log (measured on prod 2026-09-19): 11k lines a day per tab burying every line someone
+# caused. The same route answered with a failure still logs at WARNING/ERROR.
+_POLLED_ROUTES = frozenset(
+    {
+        "/api/me",
+        "/api/me/notifications/unread_count",
+        "/api/messages/unread_count",
+        "/api/downloads",
+        "/api/downloads/index",
+        "/api/downloads/usage",
+        "/api/sync/my-status",
+        "/api/admin/scheduler",
+        "/api/admin/downloads",
+        "/api/admin/downloads/storage",
+        "/api/plex/subtitle/{rating_key}/{sub_ord}/status",
+    }
+)
 
 # Not `siftlode.logs`: this is the replacement for uvicorn's ACCESS log, and `siftlode.http` is
 # what an operator pins a level on when they want request lines and nothing else. The module it
@@ -687,7 +746,9 @@ async def log_requests(request, call_next):
         raise
     duration_ms = round((time.perf_counter() - started) * 1000, 1)
     status = response.status_code
-    quiet = request.url.path.startswith(_QUIET_PREFIXES)
+    quiet = request.url.path.startswith(_QUIET_PREFIXES) or (
+        request.method == "GET" and _route_template(request) in _POLLED_ROUTES
+    )
     if status >= 500:
         level = logging.ERROR
     elif status >= 400:
@@ -713,6 +774,10 @@ async def log_requests(request, call_next):
         extra={**event("http.request", **attrs), **_request_owner(request, level)},
     )
     response.headers["X-Request-Id"] = rid
+    # The browser logs its own copy of this line (frontend lib/http.ts) and must pick the same level:
+    # it learns "this one is quiet" here instead of keeping a second copy of the polled-route list.
+    if level == logging.DEBUG:
+        response.headers["X-Log-Quiet"] = "1"
     # The template, so the browser's copy of this line groups the same way (frontend lib/http.ts).
     # Only a MATCHED route's: a template never carries a path parameter's value (a share token stays
     # `{token}`), while the raw-path fallback of an unmatched request could — the browser then

backend/app/logsink.py

@@ -44,6 +44,7 @@ from app import logs
 from app.config import settings
 from app.db import engine
 from app.models import LogEvent
+from app.utils import iso
 
 QUEUE_MAX = 10_000
 BATCH_MAX = 500
@@ -343,3 +344,24 @@ def gc(db: Session, retention_days: int) -> int:
     cutoff = datetime.now(timezone.utc) - timedelta(days=max(1, retention_days))
     result = db.execute(delete(LogEvent).where(LogEvent.ts < cutoff))
     return result.rowcount or 0
+
+
+def serialize(row: LogEvent) -> dict:
+    """A stored row as the API sends it — one shape for every reader: the admin console (E22.6) and
+    a debug session's evidence list (E16)."""
+    return {
+        "id": row.id,
+        "ts": iso(row.ts),
+        "level": row.level,
+        "source": row.source,
+        "logger": row.logger,
+        "event": row.event,
+        "msg": row.msg,
+        "attrs": row.attrs,
+        "exc": row.exc,
+        "request_id": row.request_id,
+        "user_id": row.user_id,
+        "job_id": row.job_id,
+        "debug_session_id": row.debug_session_id,
+        "version": row.version,
+    }

backend/app/main.py

@@ -32,10 +32,12 @@ from app.plex import stream as plex_stream
 from app.plex import subtitles as plex_subtitles
 from app.routes import (
     admin,
+    admin_logs as admin_logs_routes,
     audit as audit_routes,
     auth as auth_routes,
     channels,
     config as config_routes,
+    debug_sessions as debug_sessions_routes,
     diagnostics as diagnostics_routes,
     discover as discover_routes,
     downloads,
@@ -272,6 +274,7 @@ app.include_router(discover_routes.router)
 app.include_router(search_routes.router)
 app.include_router(me.router)
 app.include_router(diagnostics_routes.router)
+app.include_router(debug_sessions_routes.router)
 app.include_router(notifications.router)
 app.include_router(messages.router)
 app.include_router(channels.router)
@@ -285,6 +288,7 @@ app.include_router(admin.router)
 app.include_router(config_routes.router)
 app.include_router(scheduler_routes.router)
 app.include_router(audit_routes.router)
+app.include_router(admin_logs_routes.router)
 app.include_router(quota.router)
 app.include_router(version.router)
 app.include_router(setup_routes.router)

backend/app/models.py

@@ -12,6 +12,7 @@ from sqlalchemy import (
     Index,
     Integer,
     JSON,
+    LargeBinary,
     SmallInteger,
     String,
     Text,
@@ -241,6 +242,9 @@ class Channel(Base, TimestampMixin):
     details_synced_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     recent_synced_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     last_rss_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    # When the newest uploads were last read through the Data API because the RSS feed would not
+    # answer (`sync/runner.py` `run_feed_fallback`): the once-per-`rss_fallback_hours` clock.
+    feed_fallback_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     backfill_cursor: Mapped[str | None] = mapped_column(String(128))
     backfill_done: Mapped[bool] = mapped_column(Boolean, default=False, server_default="false")
     # True when this channel only entered the catalog because a live YouTube search
@@ -562,7 +566,15 @@ class LogEvent(Base):
     the retention job (`log_retention_days`) bounds whatever another process writes late."""
 
     __tablename__ = "log_events"
-    __table_args__ = (Index("ix_log_events_user_ts", "user_id", "ts"),)
+    __table_args__ = (
+        Index("ix_log_events_user_ts", "user_id", "ts"),
+        # E16: an issue's bundle is `WHERE debug_session_id = …`; nearly every row has none.
+        Index(
+            "ix_log_events_debug_session",
+            "debug_session_id",
+            postgresql_where="debug_session_id IS NOT NULL",
+        ),
+    )
 
     id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
     ts: Mapped[datetime] = mapped_column(DateTime(timezone=True), index=True)
@@ -581,6 +593,52 @@ class LogEvent(Base):
     version: Mapped[str | None] = mapped_column(String(64))
 
 
+class DebugSession(Base):
+    """One recording: Start → reproduce → Stop (E16, app/debugsession.py). While it is open, every
+    request of its user that names it (`X-Debug-Session`) is logged at `level` and tagged with `id`,
+    and the issue it ends in is built from the rows carrying that tag. `until` is the hard cap the
+    server set at Start; an open session past it is over whether or not the sweep has closed it yet.
+    One OPEN session per user (`uq_debug_sessions_open_per_user`, partial on `ended_at IS NULL`)."""
+
+    __tablename__ = "debug_sessions"
+    __table_args__ = (
+        Index(
+            "uq_debug_sessions_open_per_user",
+            "user_id",
+            unique=True,
+            postgresql_where="ended_at IS NULL",
+        ),
+    )
+
+    id: Mapped[str] = mapped_column(String(16), primary_key=True)
+    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
+    level: Mapped[str] = mapped_column(String(8))
+    started_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))
+    until: Mapped[datetime] = mapped_column(DateTime(timezone=True))
+    ended_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    # app/debugsession.py `EndReason`: stopped by the user, or past `until`.
+    ended_reason: Mapped[str | None] = mapped_column(String(16))
+    issue_url: Mapped[str | None] = mapped_column(String(512))
+    # The issue being written from it (E16 S3; app/debugsession.py `save_draft` holds its shape).
+    draft: Mapped[dict | None] = mapped_column(JSONB)
+
+
+class DebugScreenshot(Base):
+    """A screenshot attached to a debug session (E16) — pasted, dropped, or captured from the pill.
+    Stored in the row: bounded per session (app/debugsession.py), and gone with it by cascade."""
+
+    __tablename__ = "debug_screenshots"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    session_id: Mapped[str] = mapped_column(
+        ForeignKey("debug_sessions.id", ondelete="CASCADE"), index=True
+    )
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))
+    mime: Mapped[str] = mapped_column(String(16))
+    size: Mapped[int] = mapped_column(Integer)
+    data: Mapped[bytes] = mapped_column(LargeBinary)
+
+
 class AppState(Base):
     """Single-row global app state (admin-controlled)."""
 

backend/app/plex/query.py

@@ -298,10 +298,6 @@ class LibraryFilters:
         }
 
 
-def like_escape(s: str) -> str:
-    return s.replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_")
-
-
 # --- Watch-state scope (shared by the /library grid AND the /facets aggregation) ---------------
 #
 # The `show` scope (all | watched | in_progress | unwatched) filters the browse result by per-user

backend/app/plex/rollup.py

@@ -43,7 +43,9 @@ def rollup(cards: list[dict]) -> dict:
     ]
     resume = None
     if inprog:
-        resume = inprog[-1]  # continue the latest-started episode
+        # The LAST in-progress episode in broadcast order — no timestamp is consulted. Home's
+        # `discover.queries.next_episode` picks the same one, so both Resume buttons agree.
+        resume = inprog[-1]
     else:
         resume = next((c for c in cards if c.get("status") != "watched"), None)
     return {

backend/app/plex/stream.py

@@ -60,8 +60,10 @@ _WARMUP_SEG_TIMEOUT_S = 8.0
 # its index for that one. See `segment_name` for why this is a constant and not a comment.
 _VIDEO_VARIANT = "0"
 _SESSION_IDLE_S = 600  # reap a session with no access for this long
-# A session directory is named `{rating_key}_{int(start_s)}_{tag}_{aoff:+.2f}` (see start_session);
-# before multi-audio it was just `{rating_key}_{int(start_s)}`. `sweep_orphans` deletes ONLY names
+# A session directory is named `{rating_key}_u{user_id}_{int(start_s)}_{tag}_{aoff:+.2f}` (see
+# start_session); before per-viewer sessions it was `{rating_key}_{int(start_s)}_{tag}_{aoff:+.2f}`,
+# and before multi-audio just `{rating_key}_{int(start_s)}` — the older shapes stay sweepable, since a
+# restart leaves them behind like any other. `sweep_orphans` deletes ONLY names
 # matching one of those two shapes: `_HLS_ROOT` is admin-configurable (PLEX_HLS_DIR), so it may
 # legitimately point at a shared scratch path we do not own, and a blanket "delete every directory
 # under the root" would take the neighbours with it.
@@ -72,7 +74,9 @@ _SESSION_IDLE_S = 600  # reap a session with no access for this long
 # non-numeric rating_key would merely leave its directory unswept, which is the safe direction to
 # fail. Covered by test_plex_stream.py — this regex is the only thing standing between the sweep
 # and someone else's data.
-_SESSION_DIR_RE = re.compile(r"^\d+_\d+(_[^_]+_[+-]\d+\.\d{2})?$")
+_SESSION_DIR_RE = re.compile(
+    r"^\d+_\d+(_[^_]+_[+-]\d+\.\d{2})?$|^\d+_u\d+_\d+_[^_]+_[+-]\d+\.\d{2}$"
+)
 # When this process started. `sweep_orphans` only deletes directories older than this: everything
 # newer belongs to a session THIS run created, and since `start_session` reuses a directory path
 # for the same (rating_key, offset, tag), "stale name" is not the same as "stale directory".
@@ -88,7 +92,16 @@ _PROCESS_START = time.time()
 _MTIME_GRACE_S = 2.0
 
 _lock = threading.Lock()
-_sessions: dict[str, "HlsSession"] = {}
+# Keyed by VIEWER and item, (user_id, rating_key). Keyed by the item alone, a second account opening
+# the same film `_kill`ed the first one's session: the displaced viewer got a 404, reclaimed at its
+# playhead, and so evicted the other in turn — two people could not watch one film at once. (One
+# account on two devices still shares a session; that case ends in the player's bounded reclaim.)
+_sessions: dict[tuple[int, str], "HlsSession"] = {}
+# How many live sessions one account may hold at once (two devices, or a next item starting while the
+# last one winds down). A new one past it replaces that account's least recently used — whose waiting
+# session request then returns at once, since `wait_for` watches the killed ffmpeg — so one account
+# can neither pile up film-sized scratch copies nor park more than this many request workers.
+_MAX_SESSIONS_PER_USER = 2
 
 
 class HlsSession:
@@ -102,16 +115,17 @@ class HlsSession:
         transcode: bool = False,
         hw: bool = False,
         tonemap: bool = False,
+        user_id: int = 0,
     ):
-        # Unguessable per-session id, carried in the URLs the client is handed. Sessions are keyed
-        # by rating_key alone, so a seek-restart or a SECOND viewer of the same item replaces the
-        # registered one — and the old viewer's next request for `seg_12.ts`, resolved by rating_key,
-        # was answered 200 with the NEW session's twelfth segment, produced from a different offset
+        # Unguessable per-session id, carried in the URLs the client is handed. A seek-restart
+        # replaces the viewer's registered session for the item — and the old player's next request
+        # for `seg_12.ts`, resolved by (viewer, rating_key) alone, was answered 200 with the NEW session's twelfth segment, produced from a different offset
         # under `-copyts`. Wrong bytes, not an error, so the client's reclaim never fired on it
         # (deep-review round 5). A request naming a session that is no longer registered is a 404,
         # which the player recovers from by restarting at the playhead.
         self.id = secrets.token_urlsafe(9)
-        self.key = key
+        self.key = key  # the item's rating_key (what the logs name)
+        self.user_id = user_id  # whose session it is: the registry key is (user_id, key)
         self.dir = directory
         self.proc = proc
         self.transcode = transcode  # video re-encoded (non-h264 source), not stream-copied
@@ -637,29 +651,47 @@ def _kill(s: HlsSession) -> None:
     shutil.rmtree(s.dir, ignore_errors=True)
 
 
-def _enforce_cap(cap: int) -> None:
-    # Caller holds _lock. Only TRANSCODE sessions count toward plex_max_transcodes — remux
-    # (stream-copy) and direct-serve are cheap and deliberately uncapped (see config.py:
-    # plex_max_transcodes, and the user-facing config hint). Drop the least-recently-accessed
-    # transcode sessions over the cap, leaving any concurrent remux streams untouched.
-    tx = [(key, s) for key, s in _sessions.items() if s.transcode]
-    if len(tx) <= cap:
-        return
-    for key, s in sorted(tx, key=lambda kv: kv[1].last_access)[: len(tx) - cap]:
-        # Somebody's playback stops here. The route turns the missing session into a retryable
-        # 404 and the player restarts at the playhead, so from the server nothing failed — and
-        # "my film keeps rebuffering" has no other explanation anywhere.
-        log.info(
-            "a transcode session was dropped to stay under the cap",
-            extra=logs.event("plex.stream.session_culled", key=key, cap=cap, sessions=len(tx)),
-        )
-        _kill(s)
-        _sessions.pop(key, None)
+def _enforce_caps(user_id: int, max_transcodes: int, max_sessions: int) -> None:
+    """Caller holds _lock. Three bounds, applied after a session is registered, each dropping the
+    least recently accessed sessions over it:
+
+    * this account's own sessions (`_MAX_SESSIONS_PER_USER`) — first, so a single account filling the
+      box evicts itself before anyone else;
+    * TRANSCODE sessions (plex_max_transcodes): the CPU/GPU-heavy ones;
+    * EVERY session (plex_max_sessions). A remux is cheap on the CPU but not on the disk: each one is a
+      whole segmented copy of the film under `_HLS_ROOT`, written faster than realtime. Counted only
+      by the transcode cap, N distinct items were N ffmpegs and N film-sized scratch directories.
+
+    Somebody's playback stops at each drop. The route turns the missing session into a retryable 404
+    and the player restarts at the playhead, so from the server nothing failed — and "my film keeps
+    rebuffering" has no other explanation anywhere, hence the line."""
+
+    def cull(pool: list[tuple[tuple[int, str], HlsSession]], cap: int, bound: str) -> None:
+        if len(pool) <= cap:
+            return
+        for reg, sess in sorted(pool, key=lambda kv: kv[1].last_access)[: len(pool) - cap]:
+            log.info(
+                "a session was dropped to stay under a cap",
+                extra=logs.event(
+                    "plex.stream.session_culled",
+                    key=sess.key,
+                    bound=bound,
+                    cap=cap,
+                    sessions=len(pool),
+                ),
+            )
+            _kill(sess)
+            _sessions.pop(reg, None)
+
+    cull([kv for kv in _sessions.items() if kv[0][0] == user_id], _MAX_SESSIONS_PER_USER, "user")
+    cull([kv for kv in _sessions.items() if kv[1].transcode], max_transcodes, "transcode")
+    cull(list(_sessions.items()), max_sessions, "total")
 
 
 def start_session(
     db: DbSession,
     item: PlexItem,
+    user_id: int,
     start_s: float,
     audio_ord: int | None = None,
     aoff: float = 0.0,
@@ -679,6 +711,7 @@ def start_session(
     # session respawn (the HW->SW fallback) must not pick up a mid-playback config change.
     loudnorm = sysconfig.get_bool(db, "plex_audio_loudnorm")
     key = item.rating_key
+    reg = (user_id, key)  # the registry key: one session per viewer per item
     start_s = max(0.0, float(start_s))
     audio_langs = _probe_audio_langs(src) if multi else []
     is_multi = len(audio_langs) > 1  # only worth a master playlist when there really are ≥2 tracks
@@ -691,7 +724,7 @@ def start_session(
     # the tag with a DASH — `_SESSION_DIR_RE` treats the tag as one underscore-free field, and that
     # regex is the only thing keeping the orphan sweep off a shared scratch path (see its comment).
     tag = ("multi" if is_multi else str(audio_ord)) + ("-ln" if loudnorm else "")
-    directory = _HLS_ROOT / f"{key}_{int(start_s)}_{tag}_{aoff:+.2f}"
+    directory = _HLS_ROOT / f"{key}_u{user_id}_{int(start_s)}_{tag}_{aoff:+.2f}"
 
     def _seg(i: int) -> Path:
         return directory / segment_name(i, _VIDEO_VARIANT if variants else None)
@@ -717,9 +750,9 @@ def start_session(
         # platform without fork (the API always runs in a Linux container in prod) it's simply omitted.
         preexec = _sw_child_preexec if (transcode and not hw and os.name == "posix") else None
         with _lock:
-            if replace_only is not None and _sessions.get(key) is not replace_only:
+            if replace_only is not None and _sessions.get(reg) is not replace_only:
                 return None  # superseded/culled while we waited out of lock — don't clobber the newer one
-            old = _sessions.pop(key, None)
+            old = _sessions.pop(reg, None)
             if old is not None:
                 _kill(old)
             shutil.rmtree(directory, ignore_errors=True)
@@ -753,8 +786,9 @@ def start_session(
                 transcode=transcode,
                 hw=hw,
                 tonemap=tonemap,
+                user_id=user_id,
             )
-            _sessions[key] = s
+            _sessions[reg] = s
             # The one line that says which pipeline a session actually got. Everything downstream
             # — the cap, the HW→SW fallback, the subtitle offset — is about this choice, and until
             # now it was only inferable from the ffmpeg command nobody keeps.
@@ -770,9 +804,13 @@ def start_session(
                     start_s=round(start_s, 1),
                 ),
             )
-            # Admin-configurable concurrency cap (Configuration → Plex → Max concurrent transcodes);
-            # at least 1 so playback can't be capped to zero.
-            _enforce_cap(max(1, sysconfig.get_int(db, "plex_max_transcodes")))
+            # Admin-configurable caps (Configuration → Plex); at least 1 each so playback can't be
+            # capped to zero.
+            _enforce_caps(
+                user_id,
+                max(1, sysconfig.get_int(db, "plex_max_transcodes")),
+                max(1, sysconfig.get_int(db, "plex_max_sessions")),
+            )
         return s
 
     s = _spawn(*_select_encode(db, item, transcode, src))
@@ -798,7 +836,7 @@ def start_session(
             # turns a None return into a "Media file not found on disk" 404 — dishonest for a file that
             # exists. A (dead) session instead degrades to a retryable 404 ("No active playback session" /
             # "Not available yet") the client re-requests.
-            return current_session(key) or s
+            return current_session(user_id, key) or s
         s = respawned
         ready = wait_for(_seg(0), timeout=25.0, proc=s.proc)
     if ready:
@@ -829,9 +867,9 @@ def start_session(
     return s
 
 
-def current_session(key: str) -> HlsSession | None:
+def current_session(user_id: int, key: str) -> HlsSession | None:
     with _lock:
-        s = _sessions.get(key)
+        s = _sessions.get((user_id, key))
         if s is not None:
             s.last_access = time.time()
         return s
@@ -1060,21 +1098,21 @@ def reap_idle(finished_idle_s: float = _FINISHED_IDLE_S) -> int:
     now = time.time()
     dropped = 0
     with _lock:
-        for key, s in list(_sessions.items()):
+        for reg, s in list(_sessions.items()):
             done = s.proc.poll() is not None
             idle = now - s.last_access
             if idle > _SESSION_IDLE_S or (done and idle > finished_idle_s):
                 _kill(s)
-                _sessions.pop(key, None)
+                _sessions.pop(reg, None)
                 dropped += 1
     return dropped
 
 
-def touch_session(key: str) -> None:
-    """Say a viewer is still there for `key`, without fetching anything. `last_access` used to move
+def touch_session(user_id: int, key: str) -> None:
+    """Say this viewer is still there for `key`, without fetching anything. `last_access` used to move
     only on an HLS file fetch, which a paused player does not do — so the only way to keep a paused
     viewer's session alive was to keep EVERY abandoned one just as long."""
     with _lock:
-        s = _sessions.get(key)
+        s = _sessions.get((user_id, key))
         if s is not None:
             s.last_access = time.time()

backend/app/plex/subtitles.py

@@ -461,11 +461,18 @@ _FULL_POOL = ThreadPoolExecutor(max_workers=2, thread_name_prefix="plex-subs-ful
 # which time something has finished.
 _MAX_WINDOWS_INFLIGHT = 8
 _MAX_FULL_INFLIGHT = 6
+# …of which one account may hold this many. The full-pass slots are minutes each, and a hostile (or
+# merely curious) account opening subtitles on film after film could otherwise hold all of them while
+# everyone else's tracks never completed. A viewer over their share still gets windows — the part
+# that makes a track watchable now — just not another whole-file read until one of theirs ends.
+_MAX_FULL_PER_USER = 3
 _MAX_TRACK_WINDOWS = 2
 
 _LOCK = threading.Lock()
 # Queued or running jobs → the absolute span a window job reads (None for a full pass).
 _INFLIGHT: dict[tuple, tuple[float, float] | None] = {}
+# rating_key → the account whose poll queued that item's full pass (see _MAX_FULL_PER_USER).
+_FULL_OWNERS: dict[str, int] = {}
 # Track-level failures: a track that cannot be served at all (no item, a bitmap track, Plex down…).
 _FAILURES: dict[str, tuple[str, float]] = {}
 # rating_key → when its full pass last failed (see FULL_RETRY_S).
@@ -515,6 +522,7 @@ def reset_state() -> None:
     global _STOPPING
     with _LOCK:
         _INFLIGHT.clear()
+        _FULL_OWNERS.clear()
         _FAILURES.clear()
         _FULL_FAILED.clear()
         _WIN_FAILED.clear()
@@ -598,7 +606,7 @@ def _window_failed(key: str, at: float) -> bool:
         return any(a <= at <= b for a, b, _ in _live_window_failures(key))
 
 
-def ensure(rating_key: str, sub_ord: int, at: float = 0.0) -> dict:
+def ensure(rating_key: str, sub_ord: int, at: float = 0.0, viewer: int = 0) -> dict:
     """State of one subtitle track, scheduling whatever extraction is still missing. NEVER blocks.
 
     ``ready`` = fully extracted · ``partial`` = usable, covers ``at``, still growing · ``preparing``
@@ -641,8 +649,23 @@ def ensure(rating_key: str, sub_ord: int, at: float = 0.0) -> dict:
             if edge - at <= LOOKAHEAD_S and edge < _FULL_END_S:
                 probe = edge + 1.0
                 want_window = not _window_failed(key, probe)
-        _schedule(rating_key, sub_ord, probe, want_window=want_window, want_full=not full_failed)
-    return {"state": "partial" if covered else "preparing", "code": None, "gen": gen}
+        _schedule(
+            rating_key,
+            sub_ord,
+            probe,
+            want_window=want_window,
+            want_full=not full_failed,
+            viewer=viewer,
+        )
+    # `growing`: whether the track will fill in on its own. False once the full pass has failed and
+    # is backed off — a partial track then stays partial until a window is asked for, so the player
+    # may poll slowly (only to read ahead of an edge) instead of every two seconds for the whole film.
+    return {
+        "state": "partial" if covered else "preparing",
+        "code": None,
+        "gen": gen,
+        "growing": not full_failed,
+    }
 
 
 def cached_track(rating_key: str, sub_ord: int) -> tuple[str | None, str | None]:
@@ -659,7 +682,12 @@ def cached_track(rating_key: str, sub_ord: int) -> tuple[str | None, str | None]
 
 
 def _schedule(
-    rating_key: str, sub_ord: int, at: float, want_window: bool, want_full: bool = True
+    rating_key: str,
+    sub_ord: int,
+    at: float,
+    want_window: bool,
+    want_full: bool = True,
+    viewer: int = 0,
 ) -> None:
     """Kick off the jobs this track still needs: the window that makes it watchable now, and the one
     full pass that makes it complete. A 1 s status poll (or a second viewer) joins a job already
@@ -692,8 +720,15 @@ def _schedule(
                 ident = ("win", rating_key, sub_ord, w_start)
                 _INFLIGHT[ident] = (w_start, w_start + WINDOW_PRE_S + WINDOW_LEN_S)
                 jobs.append((ident, w_start))
-        if want_full and n_full < _MAX_FULL_INFLIGHT and ("full", rating_key) not in _INFLIGHT:
+        mine = sum(1 for owner in _FULL_OWNERS.values() if owner == viewer)
+        if (
+            want_full
+            and n_full < _MAX_FULL_INFLIGHT
+            and ("full", rating_key) not in _INFLIGHT
+            and mine < _MAX_FULL_PER_USER
+        ):
             _INFLIGHT[("full", rating_key)] = None
+            _FULL_OWNERS[rating_key] = viewer
             jobs.append((("full", rating_key), None))
     for ident, window_start in jobs:
         pool = _FULL_POOL if window_start is None else _WIN_POOL
@@ -757,6 +792,8 @@ def _run(
     finally:
         with _LOCK:
             _INFLIGHT.pop(ident, None)
+            if ident[0] == "full":
+                _FULL_OWNERS.pop(rating_key, None)
 
 
 def _pass_failed(
@@ -822,10 +859,13 @@ def _extract_and_publish(rating_key: str, sub_ord: int, window_start: float | No
             for i, s in enumerate(subs)
             if s.get("index") is not None and not _is_bitmap(s)
         }
-    start = window_start or 0.0
+    # A full pass starts where every track's leading coverage ends: a pass that ran out of time
+    # (`EXTRACT_TIMEOUT_S`) kept what it reached, and restarting from 0 each `FULL_RETRY_S` meant a file
+    # too big to read in one go never completed. Windows handle an offset start already; so does this.
+    start = window_start if window_start is not None else _full_pass_start(rating_key, targets)
     length = (WINDOW_LEN_S + WINDOW_PRE_S) if window_start is not None else None
     end = _FULL_END_S if length is None else start + length
-    texts, clean = _ffmpeg_extract(str(src), sorted(targets), window_start, length)
+    texts, clean = _ffmpeg_extract(str(src), sorted(targets), start or None, length)
     for emb_ord, vtt in texts.items():
         key = cache_key(rating_key, targets[emb_ord])
         # A pass that exited non-zero holds only what ffmpeg reached before it died. Claim no more
@@ -846,6 +886,24 @@ def _extract_and_publish(rating_key: str, sub_ord: int, window_start: float | No
             _pass_failed(rating_key, [key], window_start, (covered_end, end))
 
 
+def _full_pass_start(rating_key: str, targets: dict[int, int]) -> float:
+    """Where the full pass may begin: the end of the span from 0 that EVERY target track already has
+    (one read feeds them all, so the least-covered track decides), backed off by `WINDOW_PRE_S` so a
+    cue running across the join is read whole — `merge_vtt` folds the overlap. 0 when any track has
+    nothing from the start."""
+    ends = []
+    for ord_ in targets.values():
+        key = cache_key(rating_key, ord_)
+        ranges, _ = read_meta(key) if _exists(_vtt_path(key)) else ([], False)
+        lead = [b for a, b in ranges if a <= 0.0]
+        if not lead:
+            return 0.0
+        ends.append(max(lead))
+    if not ends:
+        return 0.0
+    return max(0.0, float(f"{min(ends) - WINDOW_PRE_S:.3f}"))
+
+
 def _sidecar_vtt(db: Session, stream: dict) -> str:
     """An external subtitle file, fetched through Plex and converted to WebVTT."""
     with PlexClient(db) as plex:
@@ -884,9 +942,10 @@ def _ffmpeg_extract(
             cmd += ["-map", f"0:s:{emb_ord}"]
             if length is not None:
                 cmd += ["-t", f"{length:.3f}"]
+            if start:
                 # The input seek lands on the keyframe at or BEFORE `start`, so a cue already running
                 # at `start` comes out at a negative time — and by default the muxer then shifts the
-                # WHOLE output so that cue sits at 0: every cue of the window late by the distance to
+                # WHOLE output so that cue sits at 0: every cue of the read late by the distance to
                 # that keyframe (1–5 s measured on a real library file, a whole GOP on a synthetic
                 # one), and doubled for good once the full pass merged in beside it. Kept negative, the
                 # times are exact on the zero-based clock (`_vtt_ts_to_s` reads the sign).

backend/app/quota.py

@@ -37,6 +37,7 @@ class QuotaAction:
     PLAYLISTS_DELETE = "playlists_delete"
     VIDEOS_BACKFILL_RECENT = "videos_backfill_recent"
     VIDEOS_BACKFILL_FULL = "videos_backfill_full"
+    VIDEOS_FEED_FALLBACK = "videos_feed_fallback"
     VIDEOS_ENRICH = "videos_enrich"
     VIDEOS_LOOKUP = "videos_lookup"
     VIDEOS_SEARCH = "videos_search"

backend/app/refusal.py

@@ -0,0 +1,37 @@
+"""A request the app refuses, said in a way the UI can put in the reader's language.
+
+Every refusal the API answers carries a structured `detail` — `{code, reason, …params}` — and the client
+translates it (`lib/api/core.ts` `localizeDetail`). A bare English string reached the Hungarian UI
+verbatim: the blocking error dialog, and every inline surface that printed `HttpError.detail`, showed
+whatever sentence the route happened to hand-write. `refused` is the generic family
+(`errors.refused.<reason>`, the params interpolated into the sentence); the older specific codes
+(`not_found`, `youtube`, `playlist`, the admin refusals, …) stay, since each is already translated.
+
+A test (`test_http_details.py`) reads every `HTTPException` in the app and fails on a string detail,
+and the frontend's contract test requires every `refused(…, "<reason>")` to be named in both
+languages — so the rule is enforced, not described.
+"""
+
+from fastapi import HTTPException
+
+
+def refused(status: int, reason: str, **params: object) -> HTTPException:
+    """The refusal to raise: `raise refused(409, "view_name_taken", name=name)`. `params` travel in
+    the detail for the sentence to interpolate (`{{name}}`); keep them to values the reader may see."""
+    return HTTPException(status_code=status, detail={"code": "refused", "reason": reason, **params})
+
+
+# `sysconfig.InvalidSetting.reason` → the refusal it answers as. A dict of literals, so the frontend's
+# contract test can read every reason this can produce.
+_SETTING_REASONS = {
+    "not_a_number": "setting_not_a_number",
+    "too_low": "setting_too_low",
+    "too_high": "setting_too_high",
+    "not_a_choice": "setting_not_a_choice",
+    "no_encryption_key": "no_encryption_key",
+}
+
+
+def setting_refused(exc) -> HTTPException:
+    """A value the admin entered that `sysconfig.set_value` refused (`exc`: its `InvalidSetting`)."""
+    return refused(400, _SETTING_REASONS[exc.reason], key=exc.key, **exc.params)

backend/app/routes/_common.py

@@ -8,11 +8,14 @@ one existence-leak policy.
 
 from typing import Any, TypeVar
 
-from fastapi import HTTPException
+from fastapi import HTTPException, Request
 from sqlalchemy.orm import Session
 
 from app.db import Base
 from app.models import User
+from app.issues import gitea
+from app.refusal import refused
+from app.youtube.client import YouTubeError, refusal_reason
 
 M = TypeVar("M", bound=Base)
 
@@ -45,9 +48,53 @@ def owned_or_404(
 ) -> M:
     """Fetch a row by primary key that `user` owns, or raise 404. A row owned by someone
     else 404s (NOT 403) on purpose — a 403 would confirm the id exists to a stranger.
-    Generalizes the near-identical per-route ownership helpers (e.g. plex's
-    `_own_playlist_or_404`, the saved-views owner check)."""
+    It replaced the near-identical per-route ownership helpers, and is called directly — a thin
+    `_own_x` wrapper around it is the ad-hoc shape CLAUDE.md's patterns table rules out."""
     obj = get_or_404(db, model, id_, what=what)
     if getattr(obj, owner_attr) != user.id:
         raise not_found(what)
     return obj
+
+
+def youtube_refusal(exc: Exception) -> HTTPException:
+    """The answer to an action YouTube refused: a 422 whose reason the UI translates
+    (`errors.youtube.<reason>`). One definition, because the routes had grown three shapes of it —
+    a bare English string quoting the upstream message, a playlist-scoped reason, and nothing at
+    all (a raw 500 from the manual syncs). The upstream failure is already logged where it
+    happened (`youtube.api.error`). A failure that is not the Data API's (the search scraper's) is
+    YouTube being unavailable to us — the retryable answer."""
+    reason = refusal_reason(exc) if isinstance(exc, YouTubeError) else "unavailable"
+    return HTTPException(status_code=422, detail={"code": "youtube", "reason": reason})
+
+
+async def capped_body(request: Request, limit: int) -> bytes:
+    """The request body, refused (413 `too_large`) the moment it passes `limit` bytes while still
+    arriving. Counted, not taken from Content-Length: a declared length can be absent (chunked) or
+    wrong, and counting stops reading at the same point a declared-length check would have."""
+    body = bytearray()
+    async for chunk in request.stream():
+        body += chunk
+        if len(body) > limit:
+            raise HTTPException(status_code=413, detail={"code": "too_large"})
+    return bytes(body)
+
+
+def issue_refused(exc: gitea.GiteaError) -> HTTPException:
+    """The refusal an issue-tracker failure (E16) answers as — the send, the preview and the
+    admin's connection test alike. Literal reasons, one per case: the frontend's contract test reads
+    them to require a sentence for each in both languages."""
+    match exc.reason:
+        case "not_configured":
+            return refused(400, "issues_not_configured")
+        case "unreachable":
+            return refused(422, "issues_unreachable")
+        case "bad_token":
+            return refused(422, "issues_bad_token")
+        case "repo_not_found":
+            return refused(422, "issues_repo_not_found")
+        case "public_repo":
+            return refused(422, "issues_public_repo")
+        case "issues_disabled":
+            return refused(422, "issues_disabled")
+        case _:
+            return refused(422, "issues_rejected")

backend/app/routes/admin.py

@@ -39,6 +39,7 @@ from app.routes.auth import (
     send_verification_link,
 )
 from app.utils import canonical_email, iso, valid_email
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/admin", tags=["admin"])
 
@@ -169,7 +170,7 @@ def _activate_user_by_email(db: Session, email: str) -> None:
     user = next((u for u in candidates if u.email == email), None) or next(iter(candidates), None)
     if user is not None and not user.is_active:
         user.is_active = True
-        db.commit()
+        db.flush()  # the handler commits (CLAUDE.md: helpers flush)
 
 
 def _decide(db: Session, invite_id: int, admin: User, approved: bool) -> Invite:
@@ -179,7 +180,7 @@ def _decide(db: Session, invite_id: int, admin: User, approved: bool) -> Invite:
     # sending a duplicate decision mail, even flipping an already-approved invite to "denied" and
     # mailing a rejection to an already-active account.
     if inv.status != "pending":
-        raise HTTPException(status_code=409, detail="Invite already decided")
+        raise refused(409, "invite_decided")
     inv.status = "approved" if approved else "denied"
     inv.decided_at = datetime.now(timezone.utc)
     inv.decided_by = admin.email
@@ -191,7 +192,7 @@ def _decide(db: Session, invite_id: int, admin: User, approved: bool) -> Invite:
         target_id=inv.id,
         summary=inv.email,
     )
-    db.commit()
+    db.flush()  # the handler commits, with the activation that goes with it
     return inv
 
 
@@ -210,6 +211,9 @@ def approve_invite(
     link, has_account, hours = _welcome_mail_parts(db, inv.email)
     lang = mailtext.lang_for_email(db, inv.email)
     background.add_task(email_mod.send_access_approved, inv.email, lang, link, has_account, hours)
+    # Before the response, so the mail (a background task, after it) never describes a decision
+    # the database does not hold yet.
+    db.commit()
     return _serialize(inv, has_account=bool(_accounts_for(db, [inv.email])))
 
 
@@ -226,6 +230,7 @@ def deny_invite(
     background.add_task(
         email_mod.send_access_denied, inv.email, mailtext.lang_for_email(db, inv.email)
     )
+    db.commit()
     return _serialize(inv, has_account=bool(_accounts_for(db, [inv.email])))
 
 
@@ -242,7 +247,7 @@ def add_invite(
     """Manually whitelist an email (approved straight away). Convenience for the admin."""
     email = body.email.strip().lower()
     if not valid_email(email):
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     # Reuse a canonically-equal row instead of adding a second one for the same mailbox. Prod carries
     # exactly that pair for one person from 2026-06-16 (hartmann.peter1986@ / hartmannpeter1986@),
     # which is how an admin ends up approving the same human twice and still seeing them bounce.
@@ -259,11 +264,13 @@ def add_invite(
     inv.status = "approved"
     inv.decided_at = datetime.now(timezone.utc)
     inv.decided_by = admin.email
+    db.flush()  # a new invite's id, for the audit row — before it, the row named no target
     audit.record(
         db, admin.id, AuditAction.INVITE_ADD, target_type="invite", target_id=inv.id, summary=email
     )
-    db.commit()
+    # One transaction: the whitelisting and the activation it implies land together or not at all.
     _activate_user_by_email(db, email)
+    db.commit()
     return _serialize(inv, has_account=bool(_accounts_for(db, [email])))
 
 
@@ -366,10 +373,7 @@ def delete_invite(
     promoted to admin on its next Google sign-in). The admin has to hear that, not guess it."""
     inv = get_or_404(db, Invite, invite_id, what="invite")
     if _accounts_for(db, [inv.email]):
-        raise HTTPException(
-            status_code=409,
-            detail="That address already has an account — delete the account instead.",
-        )
+        raise refused(409, "address_has_account")
     still_allowed_by_env = _env_allowed(inv.email)
     audit.record(
         db,
@@ -435,19 +439,19 @@ def set_user_role(
     account, and can't remove the last remaining admin. Emails the user when it actually changes."""
     role = body.role
     if role not in ("user", "admin"):
-        raise HTTPException(status_code=400, detail="role must be 'user' or 'admin'")
+        raise refused(400, "invalid_role")
     target = get_or_404(db, User, user_id, what="user")
     if target.is_demo:
-        raise HTTPException(status_code=400, detail="The demo account's role can't be changed.")
+        raise refused(400, "demo_role")
     if target.id == admin.id:
-        raise HTTPException(status_code=400, detail="You can't change your own role.")
+        raise refused(400, "own_role")
     if (
         target.role == "admin"
         and role == "user"
         and not target.is_suspended
         and count_admins(db, active_only=True) <= 1
     ):
-        raise HTTPException(status_code=400, detail="Can't remove the last admin.")
+        raise refused(400, "last_admin")
     changed = target.role != role
     if changed:
         audit.record(
@@ -493,16 +497,16 @@ def set_user_suspended(
     suspended = body.suspended
     target = get_or_404(db, User, user_id, what="user")
     if target.is_demo:
-        raise HTTPException(status_code=400, detail="The demo account can't be suspended.")
+        raise refused(400, "demo_suspend")
     if target.id == admin.id:
-        raise HTTPException(status_code=400, detail="You can't suspend your own account.")
+        raise refused(400, "own_suspend")
     if (
         suspended
         and target.role == "admin"
         and not target.is_suspended
         and count_admins(db, active_only=True) <= 1
     ):
-        raise HTTPException(status_code=400, detail="Can't suspend the last active admin.")
+        raise refused(400, "last_active_admin")
     was_suspended = target.is_suspended
     if was_suspended != suspended:
         audit.record(
@@ -537,17 +541,15 @@ def admin_delete_user(
     not the demo account, not yourself (use Settings → Account), and not the last admin."""
     target = get_or_404(db, User, user_id, what="user")
     if target.is_demo:
-        raise HTTPException(status_code=400, detail="The demo account can't be deleted.")
+        raise refused(400, "demo_delete")
     if target.id == admin.id:
-        raise HTTPException(
-            status_code=400, detail="Delete your own account from Settings → Account."
-        )
+        raise refused(400, "own_delete")
     if (
         target.role == "admin"
         and not target.is_suspended
         and count_admins(db, active_only=True) <= 1
     ):
-        raise HTTPException(status_code=400, detail="Can't delete the last admin.")
+        raise refused(400, "last_admin")
     # Record BEFORE the purge — the target row (and its email) is gone afterwards.
     audit.record(
         db,
@@ -691,7 +693,7 @@ def activate_user(
     `_activate_user_by_email`). What was missing was any way to know they had to."""
     target = get_or_404(db, User, user_id, what="user")
     if target.is_demo:
-        raise HTTPException(status_code=400, detail="The demo account can't be activated.")
+        raise refused(400, "demo_activate")
     if target.is_active:
         return _serialize_user(target)  # idempotent: a double click is not an error
     if not is_allowed(db, target.email):
@@ -788,7 +790,7 @@ def add_demo_whitelist(
     sign-in). Idempotent — re-adding an existing email just returns it."""
     email = body.email.strip().lower()
     if not valid_email(email):
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     row = db.execute(select(DemoWhitelist).where(DemoWhitelist.email == email)).scalar_one_or_none()
     if row is None:
         row = DemoWhitelist(
@@ -835,7 +837,7 @@ def reset_demo(admin: User = Depends(admin_user), db: Session = Depends(get_db))
         db, admin.id, AuditAction.DEMO_RESET, summary=f"{seeded} sample playlists re-seeded"
     )
     db.commit()
-    return {"reset": True, "playlists_seeded": seeded}
+    return {"ok": True, "reset": True, "playlists_seeded": seeded}
 
 
 @router.post("/purge-discovery")
@@ -854,4 +856,4 @@ def purge_discovery(admin: User = Depends(admin_user), db: Session = Depends(get
         after=result,
     )
     db.commit()
-    return result
+    return {"ok": True, **result}

backend/app/routes/admin_logs.py

@@ -0,0 +1,216 @@
+"""The admin diagnostics console's read side (E22.6): query `log_events`, the server's stored log.
+
+Admin-only and read-only — rows leave the table through the retention job (`log_retention_days`),
+never through here. Reading is not audited: it changes nothing, and the console's live tail polls,
+so a row per read would bury the audit log's real entries.
+
+What a row holds was redacted when it was written (`logs.record_fields`, and the ingest route for a
+browser's rows), so this serves the columns as they are; a value the redactor took out reads as
+`[redacted]` / `[email]`, which is the point — the console shows that something was there.
+
+Paging is a keyset over `(ts desc, id desc)`: a browser row's `ts` is clamped into its consent
+window, so `ts` alone is not unique, and an offset would skip or repeat rows while the writer adds
+new ones at the top. The live tail re-reads the first page rather than asking for "ids after N":
+several processes write this table, and a batch's ids are taken when it inserts, not when it
+commits, so a slower batch can land below an id the tail already passed — and would never show.
+"""
+
+import base64
+import binascii
+import json
+from dataclasses import dataclass
+from datetime import datetime, timezone
+from typing import Literal
+
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy import Text, and_, cast, func, or_, select
+from sqlalchemy.orm import Session
+
+from app import logsink
+from app.auth import admin_user
+from app.db import get_db
+from app.models import LogEvent, User
+from app.utils import like_escape
+
+router = APIRouter(prefix="/api/admin/logs", tags=["admin"])
+
+PAGE_MAX = 200
+# A facet list is a chip row, not a report: past this many distinct events the rest are reachable
+# through the free-text search, and the response stays small whatever a self-host logs.
+FACET_EVENTS_MAX = 100
+
+Level = Literal["TRACE", "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
+# The filters a facet can leave out of its own count (`LogFilters.conditions`).
+Facet = Literal["levels", "sources", "user", "event"]
+# `none` selects the rows that have no account / no event code (a scheduler line, an anonymous
+# request) — a real value to filter on, not the absence of a filter.
+NONE = "none"
+
+
+def _utc(value: datetime | None) -> datetime | None:
+    """A bound without a zone is UTC — the column is `timestamptz`, and a naive value would be read
+    in the database session's zone instead."""
+    if value is None or value.tzinfo is not None:
+        return value
+    return value.replace(tzinfo=timezone.utc)
+
+
+def _encode_cursor(row: LogEvent) -> str:
+    return base64.urlsafe_b64encode(json.dumps([row.ts.isoformat(), row.id]).encode()).decode()
+
+
+def _decode_cursor(cursor: str) -> tuple[datetime, int]:
+    try:
+        ts, row_id = json.loads(base64.urlsafe_b64decode(cursor.encode()))
+        return _utc(datetime.fromisoformat(ts)), int(row_id)
+    except (binascii.Error, json.JSONDecodeError, ValueError, TypeError) as exc:
+        raise HTTPException(status_code=400, detail={"code": "bad_cursor"}) from exc
+
+
+def _accounts(db: Session, user_ids: set[int]) -> dict[str, str]:
+    """The accounts a page names, by id → address. An id with no account left (erased after the
+    line was written) is simply absent, and the client shows the bare id."""
+    if not user_ids:
+        return {}
+    rows = db.execute(select(User.id, User.email).where(User.id.in_(user_ids))).all()
+    return {str(uid): email for uid, email in rows}
+
+
+@dataclass(frozen=True)
+class LogFilters:
+    """The console's filters, shared by the page and its facet counts."""
+
+    levels: list[str]
+    sources: list[str]
+    user: str | None
+    event: str | None
+    request_id: str | None
+    job_id: int | None
+    q: str | None
+    since: datetime | None
+    until: datetime | None
+
+    def conditions(self, skip: Facet | None = None) -> list:
+        """The WHERE conditions, ANDed by the caller. `skip` leaves one filter out: a facet counts
+        its own values under every OTHER filter, so picking a level does not zero the other
+        levels' counts (the way back), while a request pivot does narrow them (honest counts)."""
+        out = []
+        if self.levels and skip != "levels":
+            out.append(LogEvent.level.in_(self.levels))
+        if self.sources and skip != "sources":
+            out.append(LogEvent.source.in_(self.sources))
+        if self.user is not None and skip != "user":
+            out.append(
+                LogEvent.user_id.is_(None)
+                if self.user == NONE
+                else LogEvent.user_id == int(self.user)
+            )
+        if self.event is not None and skip != "event":
+            out.append(
+                LogEvent.event.is_(None) if self.event == NONE else LogEvent.event == self.event
+            )
+        if self.request_id is not None:
+            out.append(LogEvent.request_id == self.request_id)
+        if self.job_id is not None:
+            out.append(LogEvent.job_id == self.job_id)
+        if self.since is not None:
+            out.append(LogEvent.ts >= _utc(self.since))
+        if self.until is not None:
+            out.append(LogEvent.ts < _utc(self.until))
+        if self.q and self.q.strip():
+            like = f"%{like_escape(self.q.strip())}%"
+            out.append(
+                or_(
+                    LogEvent.msg.ilike(like),
+                    LogEvent.event.ilike(like),
+                    LogEvent.request_id.ilike(like),
+                    LogEvent.exc.ilike(like),
+                    cast(LogEvent.attrs, Text).ilike(like),
+                )
+            )
+        return out
+
+
+def log_filters(
+    levels: list[Level] = Query(default=[]),
+    sources: list[str] = Query(default=[], max_length=8),
+    user: str | None = Query(default=None, pattern=r"^(none|[0-9]{1,10})$"),
+    event: str | None = Query(
+        default=None, max_length=64, pattern=r"^(none|[a-z][a-z0-9_]*(\.[a-z0-9_]+)*)$"
+    ),
+    request_id: str | None = Query(default=None, pattern=r"^[A-Za-z0-9._-]{8,64}$"),
+    job_id: int | None = Query(default=None, ge=1),
+    q: str | None = Query(default=None, max_length=200),
+    since: datetime | None = None,
+    until: datetime | None = None,
+) -> LogFilters:
+    return LogFilters(list(levels), list(sources), user, event, request_id, job_id, q, since, until)
+
+
+@router.get("")
+def list_logs(
+    filters: LogFilters = Depends(log_filters),
+    before: str | None = Query(default=None, max_length=200),
+    limit: int = Query(default=100, ge=1, le=PAGE_MAX),
+    _: User = Depends(admin_user),
+    db: Session = Depends(get_db),
+) -> dict:
+    """One page of rows, newest first, matching every filter given (they AND together); `before`
+    continues from a previous page's `next_cursor`."""
+    query = select(LogEvent).where(*filters.conditions())
+    if before is not None:
+        ts, row_id = _decode_cursor(before)
+        # The `ts <=` conjunct is implied by the OR; it is there so the planner can bound the
+        # `ts` index scan instead of filtering every newer row first.
+        query = query.where(
+            and_(
+                LogEvent.ts <= ts,
+                or_(LogEvent.ts < ts, and_(LogEvent.ts == ts, LogEvent.id < row_id)),
+            )
+        )
+
+    # One more than asked, to know whether there is a next page without a second count query.
+    rows = (
+        db.execute(query.order_by(LogEvent.ts.desc(), LogEvent.id.desc()).limit(limit + 1))
+        .scalars()
+        .all()
+    )
+    more = len(rows) > limit
+    rows = rows[:limit]
+    return {
+        "items": [logsink.serialize(r) for r in rows],
+        "accounts": _accounts(db, {r.user_id for r in rows if r.user_id is not None}),
+        "next_cursor": _encode_cursor(rows[-1]) if more else None,
+    }
+
+
+@router.get("/facets")
+def log_facets(
+    filters: LogFilters = Depends(log_filters),
+    _: User = Depends(admin_user),
+    db: Session = Depends(get_db),
+) -> dict:
+    """What the filter chips offer, with counts: the levels, sources and accounts present, and the
+    most frequent events — each counted under every filter but its own (`LogFilters.conditions`).
+    `total` is the "all levels" count: every filter but the level one."""
+
+    def counts(col, skip: Facet, cap: int | None = None) -> list[dict]:
+        n = func.count().label("n")
+        stmt = select(col, n).where(*filters.conditions(skip)).group_by(col).order_by(n.desc(), col)
+        if cap is not None:
+            stmt = stmt.limit(cap)
+        return [
+            {"value": NONE if value is None else value, "count": count}
+            for value, count in db.execute(stmt).all()
+        ]
+
+    users = counts(LogEvent.user_id, "user")
+    total = select(func.count()).select_from(LogEvent).where(*filters.conditions("levels"))
+    return {
+        "levels": counts(LogEvent.level, "levels"),
+        "sources": counts(LogEvent.source, "sources"),
+        "events": counts(LogEvent.event, "event", FACET_EVENTS_MAX),
+        "users": [{**u, "value": str(u["value"])} for u in users],
+        "accounts": _accounts(db, {u["value"] for u in users if u["value"] != NONE}),
+        "total": db.scalar(total) or 0,
+    }

backend/app/routes/audit.py

@@ -68,4 +68,4 @@ def clear_audit(admin: User = Depends(admin_user), db: Session = Depends(get_db)
     n = db.execute(delete(AuditLog)).rowcount or 0
     audit.record(db, admin.id, AuditAction.AUDIT_CLEAR, summary=f"Cleared {n} audit entries")
     db.commit()
-    return {"cleared": n}
+    return {"ok": True, "cleared": n}

backend/app/routes/auth.py

@@ -43,6 +43,7 @@ from app.models import AuthToken, DemoWhitelist, Invite, OAuthToken, User
 from app.ratelimit import RateLimiter, client_key
 from app.security import encrypt, hash_password, hash_token, verify_password
 from app.utils import canonical_email, valid_email
+from app.refusal import refused
 
 VERIFY_TTL = timedelta(hours=24)
 # A confirmation link that rides an APPROVAL or an invitation lives longer than one the person is
@@ -378,7 +379,7 @@ async def callback(
 
     userinfo = token.get("userinfo")
     if not userinfo or not userinfo.get("sub"):
-        raise HTTPException(status_code=400, detail="No user info returned by Google")
+        raise refused(400, "google_no_userinfo")
 
     sub = userinfo["sub"]
     email = (userinfo.get("email") or "").lower()
@@ -653,15 +654,15 @@ async def request_access(
     endpoint can't be probed for throttling either."""
     email = (body.email or "").strip().lower()
     if not valid_email(email):
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     if not _request_access_limiter.allow(client_key(request)):
-        return {"status": "pending"}
+        return {"ok": True, "status": "pending"}
     if is_allowed(db, email):
-        return {"status": "pending"}  # already allowed — don't reveal it
+        return {"ok": True, "status": "pending"}  # already allowed — don't reveal it
     req = upsert_pending_invite(db, email, body.lang)
     if req.is_new:
         notify_admins_of_request(db, background, email)
-    return {"status": "pending"}
+    return {"ok": True, "status": "pending"}
 
 
 @router.post("/demo")
@@ -672,7 +673,7 @@ def demo_login(body: EmailIn, request: Request, db: Session = Depends(get_db)) -
     exactly like a non-match (authenticated=false) so the field can't be hammered as an
     enumeration oracle. On a match it sets the session and the client reloads into the app."""
     if not _demo_limiter.allow(client_key(request)):
-        return {"authenticated": False}
+        return {"ok": True, "authenticated": False}
     email = (body.email or "").strip().lower()
     if valid_email(email) and is_demo_allowed(db, email):
         demo = get_or_create_demo_user(db)
@@ -683,8 +684,8 @@ def demo_login(body: EmailIn, request: Request, db: Session = Depends(get_db)) -
         _remember_epoch(request, demo)
         # The demo key IS an address, so it is not in the line — see the denied branch above.
         log.info("signed in", extra=logs.event("auth.login.ok", method="demo", uid=demo.id))
-        return {"authenticated": True}
-    return {"authenticated": False}
+        return {"ok": True, "authenticated": True}
+    return {"ok": True, "authenticated": False}
 
 
 def _establish_session(request: Request, user: User) -> None:
@@ -815,23 +816,20 @@ def register(
     password = body.password or ""
     # Input validation is safe to reveal (independent of whether the email exists).
     if not valid_email(email):
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     if len(password) < PASSWORD_MIN_LEN:
-        raise HTTPException(
-            status_code=400,
-            detail=f"Password must be at least {PASSWORD_MIN_LEN} characters.",
-        )
+        raise refused(400, "weak_password", min=PASSWORD_MIN_LEN)
     if not sysconfig.get_bool(db, "allow_registration"):
-        raise HTTPException(status_code=403, detail="Registration is currently closed.")
+        raise refused(403, "registration_closed")
     if not _register_limiter.allow(client_key(request)):
-        return {"status": "ok"}  # silently throttle; uniform response
+        return {"ok": True, "status": "ok"}  # silently throttle; uniform response
 
     # Do the existence check + account creation OFF the response path (a background task with its own
     # session). The create path hashes the password + writes several rows + schedules emails; doing it
     # inline would make a NEW email respond measurably slower than an already-registered one (which
     # skips all that) — a timing oracle for enumeration. Off-path, any valid email responds the same.
     background.add_task(_register_account, email, password, body.lang)
-    return {"status": "ok"}
+    return {"ok": True, "status": "ok"}
 
 
 def _register_account(email: str, password: str, lang: str | None = None) -> None:
@@ -997,11 +995,11 @@ def verify_email_resend(
     mail had no way back. Uniform response + timing regardless of whether the email has a pending
     account (the lookup runs off the response path), so it can't probe for registered emails."""
     if not _verify_resend_limiter.allow(client_key(request)):
-        return {"status": "ok"}  # silently throttle; uniform response
+        return {"ok": True, "status": "ok"}  # silently throttle; uniform response
     email = (body.email or "").strip().lower()
     if valid_email(email):
         background.add_task(_resend_verify_if_eligible, email)
-    return {"status": "ok"}
+    return {"ok": True, "status": "ok"}
 
 
 def _resend_verify_if_eligible(email: str) -> None:
@@ -1091,14 +1089,14 @@ def password_reset_request(
     """Request a password-reset link. Uniform response + timing regardless of whether the email has a
     password account (the lookup runs off the response path), so it can't probe for registered emails."""
     if not _reset_limiter.allow(client_key(request)):
-        return {"status": "ok"}
+        return {"ok": True, "status": "ok"}
     email = (body.email or "").strip().lower()
     # Do the account lookup + token issue + email OFF the response path (a background task with its
     # own session), so the endpoint takes the same time for any valid email whether or not it has a
     # password account — no timing-based enumeration. Any valid email schedules the same task.
     if valid_email(email):
         background.add_task(_send_reset_if_eligible, email)
-    return {"status": "ok"}
+    return {"ok": True, "status": "ok"}
 
 
 def _send_reset_if_eligible(email: str) -> None:
@@ -1293,13 +1291,10 @@ def set_password(
         raise HTTPException(status_code=403, detail={"code": "demo"})
     new_password = body.password or ""
     if len(new_password) < PASSWORD_MIN_LEN:
-        raise HTTPException(
-            status_code=400,
-            detail=f"Password must be at least {PASSWORD_MIN_LEN} characters.",
-        )
+        raise refused(400, "weak_password", min=PASSWORD_MIN_LEN)
     if user.password_hash:
         if not verify_password(body.current_password or "", user.password_hash):
-            raise HTTPException(status_code=403, detail="Current password is incorrect.")
+            raise refused(403, "wrong_password")
     user.password_hash = hash_password(new_password)
     user.password_revoked_at = None  # same as the reset path: a password exists again
     # SA4: a password change logs out every OTHER session; re-stamp this cookie at the new epoch so

backend/app/routes/channels.py

@@ -4,7 +4,7 @@ hidden, tags) and per-channel sync state. Local reads/writes plus YouTube-side w
 
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException
+from fastapi import APIRouter, BackgroundTasks, Depends
 from pydantic import BaseModel
 from sqlalchemy import func, select, update
 from sqlalchemy.orm import Session
@@ -25,12 +25,13 @@ from app.models import (
     User,
     Video,
 )
-from app.routes._common import get_or_404, not_found, owned_or_404
+from app.routes._common import get_or_404, not_found, owned_or_404, youtube_refusal
 from app.sync.explore import explore_ingest_page
 from app.sync.runner import backfill_channel_now, run_recent_backfill
 from app.sync.subscriptions import apply_channel_details
 from app.utils import iso
 from app.youtube.client import YouTubeClient, YouTubeError
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/channels", tags=["channels"])
 
@@ -383,12 +384,9 @@ def explore_channel(
     backfill quota reserve; blocked for the demo account (it spends shared quota)."""
     channel = get_or_404(db, Channel, channel_id, what="channel")
     if _is_blocked(db, user, channel_id):
-        raise HTTPException(status_code=403, detail="You've blocked this channel.")
+        raise refused(403, "channel_blocked")
     if quota.backfill_reserve_reached():
-        raise HTTPException(
-            status_code=429,
-            detail="The shared daily quota reserve is reached — try exploring later.",
-        )
+        raise refused(429, "quota_reserve")
 
     # Record/refresh the exploration (DB only) before ingesting, so the explorer can see the
     # videos as soon as they land. Flag the channel ephemeral unless it's organically followed.
@@ -424,8 +422,9 @@ def explore_channel(
                 channel = db.get(Channel, channel_id)
             result = explore_ingest_page(db, yt, channel, page_token)
     except YouTubeError as exc:
-        raise HTTPException(status_code=422, detail=f"YouTube couldn't load this channel: {exc}")
+        raise youtube_refusal(exc)
     return {
+        "ok": True,
         "channel_id": channel_id,
         "ingested": result["ingested"],
         "next_page_token": result["next_page_token"],
@@ -507,6 +506,7 @@ def update_channel(
         background.add_task(backfill_channel_now, channel_id, user.id)
 
     return {
+        "ok": True,
         "id": channel_id,
         "priority": sub.priority,
         "hidden": sub.hidden,
@@ -541,7 +541,7 @@ def reset_backfill(
     db.commit()
     with quota.attribute(user.id, quota.QuotaAction.VIDEOS_BACKFILL_RECENT):
         run_recent_backfill(db, [channel], max_channels=1)
-    return {"id": channel_id, "reset": True}
+    return {"ok": True, "id": channel_id, "reset": True}
 
 
 @router.post("/{channel_id}/subscribe")
@@ -562,7 +562,7 @@ def subscribe(
         )
     ).scalar_one_or_none()
     if existing is not None:
-        raise HTTPException(status_code=409, detail="Already subscribed to this channel.")
+        raise refused(409, "already_subscribed")
     with (
         quota.attribute(user.id, quota.QuotaAction.CHANNELS_SUBSCRIBE),
         YouTubeClient(db, user) as yt,
@@ -583,9 +583,7 @@ def subscribe(
             if "subscriptionDuplicate" in exc.reason.split(","):
                 yt_sub_id = ""
             else:
-                raise HTTPException(
-                    status_code=422, detail=f"YouTube couldn't subscribe you: {exc}"
-                )
+                raise youtube_refusal(exc)
         # Enrich a stub channel (title/thumbnail/subscriber count) so it shows up properly right
         # away, on BOTH the normal and the desync path — a resurfaced stub still needs metadata to
         # render. Keep the client open (we're still inside the `with`); a metadata failure here
@@ -622,7 +620,7 @@ def subscribe(
             .values(via_explore=False)
         )
     db.commit()
-    return {"subscribed": channel_id}
+    return {"ok": True, "subscribed": channel_id}
 
 
 @router.delete("/{channel_id}/subscription")
@@ -636,10 +634,7 @@ def unsubscribe(
     should Hide instead."""
     sub = _user_subscription(db, user, channel_id)
     if not sub.yt_subscription_id:
-        raise HTTPException(
-            status_code=400,
-            detail="No YouTube subscription id on record — sync subscriptions first.",
-        )
+        raise refused(400, "no_subscription_id")
     try:
         with (
             quota.attribute(user.id, quota.QuotaAction.CHANNELS_UNSUBSCRIBE),
@@ -649,10 +644,10 @@ def unsubscribe(
     except YouTubeError as exc:
         # 422 (a real, explainable error → speaking modal), not 502 which the client treats as
         # a transient "connection lost" gateway blip.
-        raise HTTPException(status_code=422, detail=f"YouTube couldn't unsubscribe you: {exc}")
+        raise youtube_refusal(exc)
     db.delete(sub)
     db.commit()
-    return {"unsubscribed": channel_id}
+    return {"ok": True, "unsubscribed": channel_id}
 
 
 @router.get("/blocked/list")
@@ -693,7 +688,7 @@ def block_channel(
             )
         )
         db.commit()
-    return {"blocked": channel_id}
+    return {"ok": True, "blocked": channel_id}
 
 
 @router.delete("/{channel_id}/block")
@@ -708,7 +703,7 @@ def unblock_channel(
         )
     )
     db.commit()
-    return {"unblocked": channel_id}
+    return {"ok": True, "unblocked": channel_id}
 
 
 class AttachTagIn(BaseModel):
@@ -743,7 +738,7 @@ def attach_tag(
             )
         )
         db.commit()
-    return {"channel_id": channel_id, "tag_id": body.tag_id}
+    return {"ok": True, "channel_id": channel_id, "tag_id": body.tag_id}
 
 
 @router.delete("/{channel_id}/tags/{tag_id}")
@@ -763,4 +758,4 @@ def detach_tag(
     if row is not None:
         db.delete(row)
         db.commit()
-    return {"channel_id": channel_id, "tag_id": tag_id}
+    return {"ok": True, "channel_id": channel_id, "tag_id": tag_id}

backend/app/routes/config.py

@@ -4,7 +4,7 @@ app.sysconfig. Secret values (e.g. SMTP password) are write-only — never retur
 import re
 from typing import Any
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy.orm import Session
 
@@ -17,6 +17,10 @@ from app.audit import AuditAction
 from app.auth import admin_user
 from app.db import get_db
 from app.models import User
+from app.refusal import refused
+from app.issues import gitea
+from app.routes._common import issue_refused, not_found
+from app.refusal import setting_refused
 
 router = APIRouter(prefix="/api/admin/config", tags=["admin"])
 
@@ -59,19 +63,16 @@ def set_config(
 ) -> dict:
     s = sysconfig.spec(key)
     if s is None:
-        raise HTTPException(status_code=404, detail="Unknown config key")
+        raise not_found("config_key")
     if "value" not in body.model_fields_set:
-        raise HTTPException(status_code=400, detail="Missing 'value'")
+        raise refused(400, "value_missing")
     if s.secret and not sysconfig.secrets_manageable():
-        raise HTTPException(
-            status_code=400,
-            detail="Set TOKEN_ENCRYPTION_KEY to store secrets in the database.",
-        )
+        raise refused(400, "no_encryption_key")
     old = None if s.secret else sysconfig.get(db, key)
     try:
         sysconfig.set_value(db, key, body.value)
-    except (TypeError, ValueError) as exc:
-        raise HTTPException(status_code=400, detail=str(exc) or "Invalid value")
+    except sysconfig.InvalidSetting as exc:
+        raise setting_refused(exc) from None
     # Never log a secret's value — only that it was changed, by whom. Non-secret values are logged
     # but with URL credentials redacted (a proxy/URL setting can embed user:pass). Skip the row when
     # a non-secret value didn't actually change (a no-op re-save shouldn't add trail noise); secrets
@@ -101,7 +102,7 @@ def reset_config(
 ) -> dict:
     s = sysconfig.spec(key)
     if s is None:
-        raise HTTPException(status_code=404, detail="Unknown config key")
+        raise not_found("config_key")
     old = None if s.secret else sysconfig.get(db, key)
     sysconfig.reset(db, key)
     audit.record(
@@ -126,8 +127,21 @@ def send_test_email(
     """Send a test email to the requesting admin using the current (DB or env) SMTP config —
     lets the admin verify the settings actually work."""
     if not email_mod.email_enabled():
-        raise HTTPException(status_code=400, detail="SMTP is not configured.")
+        raise refused(400, "smtp_off")
     sent = email_mod.send_test(user.email, mailtext.lang_for_user(user))
     if not sent:
-        raise HTTPException(status_code=422, detail="SMTP send failed — check the settings.")
-    return {"sent": True, "to": user.email}
+        raise refused(422, "smtp_failed")
+    return {"ok": True, "sent": True, "to": user.email}
+
+
+@router.post("/test-issues")
+def test_issue_tracker(
+    _: User = Depends(admin_user),
+    db: Session = Depends(get_db),
+) -> dict:
+    """Check the configured issue tracker (E16): the repository answers with this token, takes
+    issues, and is PRIVATE — the one it must be, since an issue carries its reporter's log."""
+    try:
+        return {"ok": True, **gitea.check(db)}
+    except gitea.GiteaError as exc:
+        raise issue_refused(exc) from None

backend/app/routes/debug_sessions.py

@@ -0,0 +1,412 @@
+"""Debug sessions (E16): Start → reproduce → Stop, the screenshots, and the evidence under review.
+
+The session itself — what tags a request, its cap, its level — is `app/debugsession.py`. These routes
+are the user's handle on their OWN sessions only: another user's id 404s (`owned_or_404`), including
+for an admin, who reads everyone's lines in the diagnostics console instead. The shared demo account
+cannot record: its log would interleave every visitor under one account.
+
+Screenshots arrive as a raw image body (`image/png`, `image/jpeg`, `image/webp`), not a multipart
+form — one image per request, capped while it arrives, and kept only if its bytes really are one of
+those types, whatever the Content-Type claimed.
+"""
+
+import json
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, Request, Response
+from pydantic import BaseModel, Field
+from sqlalchemy import select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.orm import Session
+
+from app import audit, debugsession, logs, logsink
+from app.audit import AuditAction
+from app.auth import require_human
+from app.db import get_db
+from app.issues import bundle, gitea
+from app.ratelimit import RateLimiter
+from app.refusal import refused
+from app.models import DebugScreenshot, DebugSession, User
+from app.routes._common import capped_body, issue_refused, not_found, owned_or_404
+from app.utils import iso
+
+router = APIRouter(prefix="/api/debug-sessions", tags=["diagnostics"])
+log = logs.get_logger(__name__)
+
+# Sessions listed in Settings → Diagnosztika, newest first: enough to reach last week's unsent draft.
+LIST_MAX = 20
+
+
+class StartIn(BaseModel):
+    level: debugsession.SessionLevel
+
+
+_view = debugsession.view
+
+# New sessions a user may open per hour (joining the running one is not counted): a session is a
+# place to keep screenshots, and this — with the per-user storage cap — bounds how many there are.
+_new_sessions = RateLimiter(max_events=20, window_seconds=3600)
+
+
+@router.post("")
+def start_session(
+    body: StartIn,
+    user: User = Depends(require_human),
+    db: Session = Depends(get_db),
+) -> dict:
+    """Start recording, or join the recording already running (another tab started it)."""
+    joining = debugsession.open_session(db, user) is not None
+    if not joining and not _new_sessions.allow(str(user.id)):
+        raise refused(429, "debug_session_rate_limited", limit=_new_sessions.max_events)
+    try:
+        session = debugsession.start(db, user, body.level)
+        db.commit()
+    except IntegrityError:
+        # A concurrent Start won the one-open-per-user index: join that one.
+        db.rollback()
+        session = debugsession.open_session(db, user)
+        if session is None:
+            raise refused(409, "debug_session_conflict") from None
+    # The rest of THIS request is part of the session too.
+    level, until = debugsession.level_for(user, session)
+    logs.set_user(user.id, level, until, session.id)
+    log.info(
+        "debug session started",
+        extra=logs.event("debug.session.started", level=session.level, until=iso(session.until)),
+    )
+    return {"ok": True, "session": _view(db, session)}
+
+
+@router.post("/{sid}/stop")
+def stop_session(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    if session.ended_at is None:
+        # Logged BEFORE the session closes, while this request still carries its tag: the last line
+        # of the evidence is the Stop itself.
+        log.info("debug session stopped", extra=logs.event("debug.session.stopped"))
+        debugsession.stop(session)
+        db.commit()
+        logs.end_session_elevation(session.id)
+    return {"ok": True, "session": _view(db, session)}
+
+
+@router.get("")
+def list_sessions(user: User = Depends(require_human), db: Session = Depends(get_db)) -> dict:
+    sessions = db.scalars(
+        select(DebugSession)
+        .where(DebugSession.user_id == user.id)
+        .order_by(DebugSession.started_at.desc())
+        .limit(LIST_MAX)
+    ).all()
+    return {"items": [_view(db, s) for s in sessions]}
+
+
+@router.get("/{sid}")
+def get_session(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    return _view(db, owned_or_404(db, DebugSession, sid, user, what="debug_session"))
+
+
+@router.get("/{sid}/events")
+def session_events(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    """The rows an issue from this session would carry — browser and server, in time order."""
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    rows, total = debugsession.bundle(db, session)
+    return {"items": [logsink.serialize(r) for r in rows], "total": total}
+
+
+# --- the draft and its export ---------------------------------------------------------------
+# The composer's own fields (steps, description…) are its business, kept whole so it reopens as it
+# was — bounded here so a draft cannot become a place to store anything else.
+FORM_MAX_BYTES = 64 * 1024
+# Zips a user may build per minute: each holds every screenshot in memory while it is built.
+_exports = RateLimiter(max_events=6, window_seconds=60)
+
+
+class DraftIn(BaseModel):
+    title: str = Field(max_length=200)
+    # The rendered markdown the export and the issue carry.
+    body: str = Field(max_length=50_000)
+    # Log rows taken out of the evidence in the review.
+    excluded: list[int] = Field(default_factory=list, max_length=debugsession.BUNDLE_MAX)
+    form: dict[str, Any] = Field(default_factory=dict)
+
+
+@router.put("/{sid}/draft")
+def save_draft(
+    sid: str,
+    body: DraftIn,
+    user: User = Depends(require_human),
+    db: Session = Depends(get_db),
+) -> dict:
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    if len(json.dumps(body.form, ensure_ascii=False).encode()) > FORM_MAX_BYTES:
+        raise HTTPException(status_code=413, detail={"code": "too_large"})
+    # Under the lock, and refused while a send is under way: the issue is being built from the draft
+    # as it was saved, and this would change it under the send.
+    debugsession.lock(db, session)
+    if debugsession.sending(session):
+        raise refused(409, "issue_sending")
+    if session.issue_url is not None:
+        # Sent: the issue is on the tracker now, and a draft edited after it would say otherwise.
+        raise refused(409, "issue_already_sent")
+    debugsession.save_draft(session, body.model_dump())
+    db.commit()
+    return {"ok": True, "session": _view(db, session)}
+
+
+@router.get("/{sid}/export")
+def export_session(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> Response:
+    """The issue as a zip — the text, the two logs and the screenshots — for an instance without an
+    issue tracker, or for sending it by hand. Built from the SAVED draft: what the composer shows is
+    what it saved."""
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    if not _exports.allow(str(user.id)):
+        raise refused(429, "export_rate_limited")
+    data = bundle.zipped(bundle.files(db, session))
+    name = f"siftlode-debug-{session.started_at:%Y%m%d-%H%M}-{session.id[:6]}.zip"
+    return Response(
+        content=data,
+        media_type="application/zip",
+        headers={
+            "Content-Disposition": f'attachment; filename="{name}"',
+            "Cache-Control": "no-store",
+        },
+    )
+
+
+# --- the issue tracker (S4) -----------------------------------------------------------------
+# Issues a user may open per hour — counted once the tracker is ASKED to open one (an answer that
+# goes missing may still have created it, so an attempt cannot be given back); finishing a half-sent
+# one, or an attempt refused before the tracker was asked, is not counted. The composer sends one at
+# a time; this is room for a bad afternoon, not a pace anything legitimate keeps up.
+_new_issues = RateLimiter(max_events=5, window_seconds=3600)
+# Attempts on the tracker per hour, creating or finishing. Deliberately NOT the budget above: a
+# half-sent issue must always be finishable, so the pace that guards creating one must never be what
+# stands between a user and their own report. This one only bounds a loop — every attempt re-reads
+# the whole bundle into memory and re-offers the pending file to the tracker, and a retry that is
+# refused for good (the tracker's own limits) never leaves `pending`. No hand reaches it.
+_sends = RateLimiter(max_events=60, window_seconds=3600)
+# The composer's live preview, rendered BY the tracker: one authenticated call each, with our token.
+# The composer's toggle fires it once per switch INTO preview — the editor is the other branch, so
+# no keystroke can change the query key while the preview is up — and react-query's cache makes an
+# unchanged draft free. (It does NOT debounce, whatever this comment used to say: a key that changes
+# per keystroke is one fetch per keystroke, measured. Showing the preview BESIDE the fields would
+# need a real debounce first.) This bounds what a loop can aim at the tracker.
+_previews = RateLimiter(max_events=60, window_seconds=60)
+
+
+def _issues_rate_limited() -> HTTPException:
+    return refused(429, "issues_rate_limited", limit=_new_issues.max_events)
+
+
+@router.post("/{sid}/issue")
+def send_issue(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    """Send the session's issue to the tracker — from the SAVED draft, as the export is built — or
+    finish a send that stopped half-way (the issue exists; only what is missing is sent)."""
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    # The session is CLAIMED for the send rather than locked through it: the tracker is slow (a
+    # dozen calls, 20 s each), and a row lock held across them would queue this user's Stop, their
+    # autosave and their screenshots behind it. They see the claim instead and are refused at once.
+    debugsession.lock(db, session)
+    if debugsession.sending(session):
+        raise refused(409, "issue_sending")
+    new = session.issue_url is None
+    if not new and not debugsession.unfinished(session):
+        return {"ok": True, "session": _view(db, session)}
+    key = str(user.id)
+    if new:
+        if not ((session.draft or {}).get("title") or "").strip():
+            raise refused(422, "issue_title_required")
+        if _new_issues.exhausted(key):
+            raise _issues_rate_limited()
+    if not _sends.allow(key):
+        raise refused(429, "issue_rate_limited", limit=_sends.max_events)
+    token = debugsession.claim_send(session)
+    db.commit()  # the claim is what everything else sees; the lock ends here
+
+    def count_new_issue() -> None:
+        if not _new_issues.allow(key):
+            raise _issues_rate_limited()
+
+    try:
+        gitea.deliver(
+            db,
+            session,
+            token=token,
+            checkpoint=db.commit,
+            before_create=count_new_issue,
+            on_created=lambda: _record_created(db, user, session),
+        )
+    except debugsession.SendClaimLost:
+        # This send outlived its lease and another one took the session over while it was still
+        # talking to the tracker. It stopped rather than writing over that one's progress — and a
+        # send IS under way, just not ours, which is what the caller needs to hear.
+        raise refused(409, "issue_sending") from None
+    except gitea.GiteaError as exc:
+        # Keep what did happen: an issue created before an upload failed stays linked, and the
+        # retry does only what is still missing.
+        raise issue_refused(exc) from None
+    except HTTPException:
+        raise  # the pace, refused before the tracker was asked
+    finally:
+        _end_send(db, session, token)
+    return {"ok": True, "session": _view(db, session)}
+
+
+def _end_send(db: Session, session: DebugSession, token: str) -> None:
+    """Give the claim back, whatever else happened. A failure here must not replace the failure that
+    brought us: a dead transaction (the database went away mid-send) is rolled back, and the claim
+    then simply ages out."""
+    try:
+        debugsession.lock(db, session)
+        debugsession.release_send(session, token)
+        db.commit()
+    except Exception:  # noqa: BLE001 — whatever went wrong here, the send's own failure is the news
+        db.rollback()
+        log.warning(
+            "a send could not give its claim back",
+            extra=logs.event("issues.claim.stuck", session_id=session.id),
+        )
+
+
+def _record_created(db: Session, user: User, session: DebugSession) -> None:
+    """The trail for the one act that takes a user's log off this instance. Staged inside the send,
+    so the checkpoint that first writes `issue_url` commits BOTH — recorded later it could be lost
+    on its own (the process dies mid-send), and no retry could write it afterwards: the next send
+    sees the link and knows the issue is not new."""
+    audit.record(
+        db,
+        user.id,
+        AuditAction.ISSUE_CREATE,
+        target_type="debug_session",
+        target_id=session.id,
+        summary=session.issue_url or "",
+    )
+
+
+class PreviewIn(BaseModel):
+    text: str = Field(max_length=50_000)
+
+
+@router.post("/{sid}/preview")
+def preview_issue(
+    sid: str,
+    body: PreviewIn,
+    user: User = Depends(require_human),
+    db: Session = Depends(get_db),
+) -> dict:
+    """The body as the tracker will render it. Gitea sanitises its own output; the composer still
+    shows it in a sandboxed frame, never in the app's own document."""
+    owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    if not _previews.allow(str(user.id)):
+        raise refused(429, "preview_rate_limited")
+    try:
+        return {"ok": True, "html": gitea.preview(db, body.text)}
+    except gitea.GiteaError as exc:
+        raise issue_refused(exc) from None
+
+
+# --- screenshots ---------------------------------------------------------------------------
+def _shot_view(shot: DebugScreenshot) -> dict:
+    return {"id": shot.id, "mime": shot.mime, "size": shot.size, "created_at": iso(shot.created_at)}
+
+
+@router.get("/{sid}/screenshots")
+def list_screenshots(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    return {"items": [_shot_view(s) for s in debugsession.screenshots(db, session)]}
+
+
+def _upload_target(
+    sid: str, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> DebugSession:
+    return owned_or_404(db, DebugSession, sid, user, what="debug_session")
+
+
+async def _image_body(request: Request) -> bytes:
+    return await capped_body(request, debugsession.SCREENSHOT_MAX_BYTES)
+
+
+@router.post("/{sid}/screenshots")
+def add_screenshot(
+    # The owner check FIRST: dependencies resolve in order, so a stranger's upload is refused
+    # before a byte of it is read.
+    session: DebugSession = Depends(_upload_target),
+    data: bytes = Depends(_image_body),
+    db: Session = Depends(get_db),
+) -> dict:
+    try:
+        shot = debugsession.add_screenshot(db, session, data)
+    except debugsession.ScreenshotRefused as exc:
+        raise _screenshot_refused(exc.code) from None
+    db.commit()
+    return {"ok": True, "screenshot": _shot_view(shot)}
+
+
+def _screenshot_refused(code: str) -> HTTPException:
+    # Literal reasons, one per case: the frontend's contract test reads them to require a sentence
+    # for each in both languages.
+    if code == "already_sent":
+        return refused(409, "screenshot_already_sent")
+    if code == "too_many":
+        return refused(422, "screenshot_too_many", limit=debugsession.SCREENSHOTS_MAX)
+    if code == "sending":
+        return refused(409, "issue_sending")
+    if code == "storage_full":
+        mb = debugsession.SCREENSHOT_USER_MAX_BYTES // (1024 * 1024)
+        return refused(422, "screenshot_storage_full", limit=mb)
+    if code == "empty":
+        return refused(422, "screenshot_empty")
+    return refused(422, "screenshot_not_an_image")
+
+
+def _session_screenshot(db: Session, sid: str, shot_id: int, user: User) -> DebugScreenshot:
+    return _screenshot_of(
+        db, owned_or_404(db, DebugSession, sid, user, what="debug_session"), shot_id
+    )
+
+
+def _screenshot_of(db: Session, session: DebugSession, shot_id: int) -> DebugScreenshot:
+    shot = db.get(DebugScreenshot, shot_id)
+    if shot is None or shot.session_id != session.id:
+        raise not_found("screenshot")
+    return shot
+
+
+@router.get("/{sid}/screenshots/{shot_id}")
+def get_screenshot(
+    sid: str, shot_id: int, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> Response:
+    shot = _session_screenshot(db, sid, shot_id, user)
+    # `nosniff`: the type was checked against the bytes at upload, and the browser must not guess.
+    return Response(
+        content=shot.data,
+        media_type=shot.mime,
+        headers={"Cache-Control": "private, max-age=3600", "X-Content-Type-Options": "nosniff"},
+    )
+
+
+@router.delete("/{sid}/screenshots/{shot_id}")
+def delete_screenshot(
+    sid: str, shot_id: int, user: User = Depends(require_human), db: Session = Depends(get_db)
+) -> dict:
+    session = owned_or_404(db, DebugSession, sid, user, what="debug_session")
+    shot = _screenshot_of(db, session, shot_id)
+    try:
+        debugsession.remove_screenshot(db, session, shot)
+    except debugsession.ScreenshotRefused as exc:
+        raise _screenshot_refused(exc.code) from None
+    db.commit()
+    return {"ok": True, "deleted": shot_id}

backend/app/routes/diagnostics.py

@@ -13,7 +13,9 @@ Nothing from the body is trusted as-is:
   * everything is redacted AGAIN with the server's own rules — the client redacts at capture, but a
     modified client would not;
   * an event below the consented level is dropped (a Részletes consent does not store what only
-    Teljes may carry), and so is the whole batch once the level has lapsed;
+    Teljes may carry), and so is the whole batch once the level has lapsed — where an open debug
+    session the request names counts as consent to ITS level (E16), and only its own events keep
+    its tag;
   * the timestamp is clamped to the consent window, so a row cannot dodge the retention job by
     claiming to come from the future.
 """
@@ -27,11 +29,12 @@ from pydantic import BaseModel, Field, ValidationError
 from sqlalchemy import insert
 from sqlalchemy.orm import Session
 
-from app import diagnostics, logs, logsink
+from app import debugsession, diagnostics, logs, logsink
 from app.auth import current_user
 from app.db import get_db
-from app.models import LogEvent, User
+from app.models import DebugSession, LogEvent, User
 from app.ratelimit import RateLimiter
+from app.routes._common import capped_body
 
 router = APIRouter(prefix="/api/diagnostics", tags=["diagnostics"])
 
@@ -60,6 +63,9 @@ class ClientEvent(BaseModel):
     attrs: dict[str, Any] | None = None
     request_id: str | None = Field(default=None, pattern=r"^[A-Za-z0-9._-]{8,64}$")
     tab_id: str | None = Field(default=None, pattern=r"^[A-Za-z0-9_-]{1,32}$")
+    # The debug session the event was captured in (E16); kept only when it is the one this request
+    # names in `X-Debug-Session` and the auth dependency found it the caller's own and open.
+    debug_session_id: str | None = Field(default=None, pattern=r"^[0-9a-f]{16}$")
     version: str | None = Field(default=None, max_length=64)
 
 
@@ -67,18 +73,6 @@ class ClientEventsIn(BaseModel):
     events: list[ClientEvent] = Field(max_length=EVENTS_MAX)
 
 
-async def _capped_body(request: Request) -> bytes:
-    """The request body, refused the moment it passes BODY_MAX_BYTES while still arriving. Counted,
-    not taken from Content-Length: a declared length can be absent (chunked) or wrong, and counting
-    stops reading at the same point a declared-length check would have."""
-    body = bytearray()
-    async for chunk in request.stream():
-        body += chunk
-        if len(body) > BODY_MAX_BYTES:
-            raise HTTPException(status_code=413, detail={"code": "too_large"})
-    return bytes(body)
-
-
 async def _parsed_events(request: Request) -> ClientEventsIn:
     """The body as the model — parsed only after the size cap, which is why this is a dependency and
     not a plain body parameter (FastAPI reads a declared body in full before anything else runs).
@@ -89,14 +83,20 @@ async def _parsed_events(request: Request) -> ClientEventsIn:
     media_type = request.headers.get("content-type", "").split(";")[0].strip().lower()
     if media_type != "application/json" and not media_type.endswith("+json"):
         raise HTTPException(status_code=415, detail={"code": "json_required"})
-    raw = await _capped_body(request)
+    raw = await capped_body(request, BODY_MAX_BYTES)
     try:
         return ClientEventsIn.model_validate_json(raw)
     except ValidationError as exc:
         raise HTTPException(status_code=422, detail=json.loads(exc.json())) from exc
 
 
-def _row(item: ClientEvent, user: User, now: datetime, window_start: datetime) -> dict[str, Any]:
+def _row(
+    item: ClientEvent,
+    user: User,
+    now: datetime,
+    window_start: datetime,
+    session: DebugSession | None,
+) -> dict[str, Any]:
     attrs = logs.redact(item.attrs) if item.attrs else None
     if attrs is not None:
         size = len(json.dumps(attrs, ensure_ascii=False, default=str).encode())
@@ -117,6 +117,9 @@ def _row(item: ClientEvent, user: User, now: datetime, window_start: datetime) -
             "attrs": attrs,
             "request_id": item.request_id,
             "user_id": user.id,
+            "debug_session_id": (
+                session.id if session and item.debug_session_id == session.id else None
+            ),
             "version": item.version,
         }
     )
@@ -126,11 +129,15 @@ def _row(item: ClientEvent, user: User, now: datetime, window_start: datetime) -
 def ingest_events(
     # The account first: dependencies resolve in order, so an anonymous caller is refused before a
     # byte of its body is read.
+    request: Request,
     user: User = Depends(current_user),
     body: ClientEventsIn = Depends(_parsed_events),
     db: Session = Depends(get_db),
 ) -> dict:
-    level = diagnostics.effective_level(user)
+    # A debug session the request names raises the level for its own events (E16): starting one is
+    # the consent to that level for its duration, whatever the user's own level is.
+    session = debugsession.from_header(db, user, request.headers.get(debugsession.HEADER))
+    level, _ = debugsession.level_for(user, session)
     if level == diagnostics.BASE:
         # Lapsed or withdrawn: the client stops streaming when it sees this.
         raise HTTPException(status_code=409, detail={"code": "diagnostics_off"})
@@ -140,7 +147,7 @@ def ingest_events(
     window_start = now - timedelta(hours=diagnostics.ELEVATION_HOURS)
     floor = logs.SEVERITY[level]
     rows = [
-        _row(item, user, now, window_start)
+        _row(item, user, now, window_start, session)
         for item in body.events
         if logs.SEVERITY[item.level] >= floor
     ]

backend/app/routes/discover.py

@@ -11,9 +11,9 @@ thing it exists to remove.
 
 from typing import Literal
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
-from sqlalchemy import select, update
+from sqlalchemy import select
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import Session
 
@@ -23,7 +23,7 @@ from app.discover import hero as hero_mod
 from app.discover import pins, rails
 from app.discover.budget import Budget, DEFAULT_BUDGET
 from app.models import ComfortPin, User
-from app.routes._common import owned_or_404
+from app.routes._common import owned_or_404, not_found
 
 router = APIRouter(prefix="/api/discover", tags=["discover"])
 
@@ -53,7 +53,9 @@ def get_discover(
     `resume` and `shelf` are built once and handed to the hero, so the two rails the hero draws from
     are not queried twice for a single page load."""
     resume = rails.continue_watching(db, user)
-    shelf = pins.shelf(db, user)
+    # Plex off → the shelf rail (and so the hero's comfort tier) goes YouTube-only like the rails
+    # beside it; the pins are kept and `GET /pins` still lists them (`pins.shelf`).
+    shelf = pins.shelf(db, user, include_plex=rails.plex_available(db))
     return {
         "budget": budget,
         "hero": hero_mod.pick(db, user, budget, seed, resume=resume, shelf=shelf),
@@ -125,7 +127,7 @@ def add_pin(
     constraint is the mechanism, not the message."""
     resolved = pins.resolve_ref(db, user, body.kind, body.ref)
     if resolved is None:
-        raise HTTPException(status_code=404, detail="Unknown item")
+        raise not_found("item")
     column, value = resolved
 
     existing = db.execute(
@@ -157,7 +159,7 @@ def add_pin(
             # between `resolve_ref` confirming it and this INSERT (a Plex sync dropping a removed
             # item), which trips the FK. Semantically that is the same "no such thing" the pre-check
             # returns above — re-raising handed the user a 500 they could do nothing with.
-            raise HTTPException(status_code=404, detail="Unknown item")
+            raise not_found("item")
         return {"ok": True, "id": winner.id, "created": False}
     return {"ok": True, "id": pin.id, "created": True}
 
@@ -180,18 +182,11 @@ def reorder_pins(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    """Rewrite the shelf order from a full list of pin ids.
+    """Rewrite the shelf order from the list of pin ids the client shows.
 
     Whole-list rather than a move-one delta: the shelf is short, and a full rewrite cannot leave two
-    tiles claiming the same slot the way an interrupted sequence of single moves can. Ids that are not
-    this user's are ignored rather than 404'd — a stale tab replaying an order that includes a pin
-    deleted meanwhile should reorder what still exists, not fail wholesale."""
-    owned = {p.id for p in pins.list_pins(db, user)}
-    for position, pin_id in enumerate(i for i in body.ids if i in owned):
-        db.execute(
-            update(ComfortPin)
-            .where(ComfortPin.id == pin_id, ComfortPin.user_id == user.id)
-            .values(position=position)
-        )
+    tiles claiming the same slot the way an interrupted sequence of single moves can. The list may be
+    PARTIAL (hidden Plex pins, a stale tab) — `pins.reorder` keeps what it leaves out in place."""
+    pins.reorder(db, user, body.ids)
     db.commit()
     return {"ok": True}

backend/app/routes/downloads.py

@@ -38,10 +38,11 @@ from app.models import (
     MediaAsset,
     User,
 )
-from app.routes._common import get_or_404, not_found
+from app.routes._common import get_or_404, not_found, owned_or_404
 from app.security import hash_password
 from app.userscope import is_messageable_user, messageable_clauses
 from app.utils import iso
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/downloads", tags=["downloads"])
 admin_router = APIRouter(prefix="/api/admin/downloads", tags=["admin-downloads"])
@@ -63,7 +64,7 @@ def resolve_source(raw: str) -> tuple[str, str]:
     as a raw URL for yt-dlp's generic extractor."""
     raw = (raw or "").strip()
     if not raw:
-        raise HTTPException(status_code=400, detail="A video link or id is required.")
+        raise refused(400, "link_required")
     if _VIDEO_ID.match(raw):
         return "youtube", raw
     if raw.startswith(("http://", "https://")):
@@ -93,7 +94,7 @@ def resolve_source(raw: str) -> tuple[str, str]:
             if _VIDEO_ID.match(vid):
                 return "youtube", vid
         return "url", raw
-    raise HTTPException(status_code=400, detail="That doesn't look like a valid video link.")
+    raise refused(400, "invalid_link")
 
 
 def _serialize(job: DownloadJob, asset: MediaAsset | None) -> dict:
@@ -166,15 +167,8 @@ def _serialize_job(db: Session, job: DownloadJob) -> dict:
     return _serialize(job, asset)
 
 
-def _own_job(db: Session, user: User, job_id: int) -> DownloadJob:
-    job = db.get(DownloadJob, job_id)
-    if job is None or job.user_id != user.id:
-        raise HTTPException(status_code=404, detail="Unknown download")
-    return job
-
-
 def _own_job_for_update(db: Session, user: User, job_id: int) -> DownloadJob:
-    """`_own_job` for a transition that moves its asset's ref count (resume, cancel, delete, redownload)
+    """The ownership check (`owned_or_404`) for a transition that moves its asset's ref count (resume, cancel, delete, redownload)
     or writes the status those decide on (pause). The job is re-read under a row lock, so two
     overlapping requests for one job run one after the other and the second decides on the first's
     committed result — never both releasing the same hold, and never a pause turning a job a cancel
@@ -183,7 +177,7 @@ def _own_job_for_update(db: Session, user: User, job_id: int) -> DownloadJob:
     The asset is locked BEFORE the job: the order a finishing worker child takes them in
     (`service.finalize_if_running`), so the two can never deadlock."""
     while True:
-        asset_id = _own_job(db, user, job_id).asset_id
+        asset_id = owned_or_404(db, DownloadJob, job_id, user, what="download").asset_id
         if asset_id is not None:
             db.execute(select(MediaAsset.id).where(MediaAsset.id == asset_id).with_for_update())
         job = db.execute(
@@ -193,7 +187,7 @@ def _own_job_for_update(db: Session, user: User, job_id: int) -> DownloadJob:
             .execution_options(populate_existing=True)
         ).scalar_one_or_none()
         if job is None:
-            raise HTTPException(status_code=404, detail="Unknown download")
+            raise not_found("download")
         if job.asset_id == asset_id:
             return job
         db.rollback()  # another request moved the job to another asset meanwhile: lock that one
@@ -240,7 +234,7 @@ def create_profile(
     name = body.name.strip()
     spec = body.spec
     if not name:
-        raise HTTPException(status_code=400, detail="A profile name is required.")
+        raise refused(400, "profile_name_required")
     maxpos = db.execute(
         select(func.coalesce(func.max(DownloadProfile.sort_order), 100)).where(
             DownloadProfile.user_id == user.id
@@ -268,16 +262,16 @@ def update_profile(
 ) -> dict:
     p = db.get(DownloadProfile, profile_id)
     if p is None or p.is_builtin or p.user_id != user.id:
-        raise HTTPException(status_code=404, detail="Unknown profile")
+        raise not_found("profile")
     sent = body.model_fields_set
     if "name" in sent:
         name = (body.name or "").strip()
         if not name:
-            raise HTTPException(status_code=400, detail="A profile name is required.")
+            raise refused(400, "profile_name_required")
         p.name = name[:80]
     if "spec" in sent:
         if body.spec is None:
-            raise HTTPException(status_code=400, detail="spec must be an object")
+            raise refused(400, "spec_not_object")
         p.spec = body.spec
     db.commit()
     return _serialize_profile(p)
@@ -289,7 +283,7 @@ def delete_profile(
 ) -> dict:
     p = db.get(DownloadProfile, profile_id)
     if p is None or p.is_builtin or p.user_id != user.id:
-        raise HTTPException(status_code=404, detail="Unknown profile")
+        raise not_found("profile")
     db.delete(p)
     db.commit()
     return {"deleted": profile_id}
@@ -319,7 +313,7 @@ def set_credential(
     """Store (encrypted) this user's cookies.txt for one supported host. Write-only: the value is
     never echoed back, logged, or audited — only the fact that it changed."""
     if not dlcreds.is_supported_host(host_key):
-        raise HTTPException(status_code=404, detail="Unknown host")
+        raise not_found("host")
     try:
         cleaned = dlcreds.validate_cookies(body.cookies)
     except dlcreds.InvalidCookies as e:
@@ -341,7 +335,7 @@ def delete_credential(
     host_key: str, user: User = Depends(require_human), db: Session = Depends(get_db)
 ) -> dict:
     if not dlcreds.is_supported_host(host_key):
-        raise HTTPException(status_code=404, detail="Unknown host")
+        raise not_found("host")
     if dlcreds.delete_credential(db, user.id, host_key):
         audit.record(
             db,
@@ -362,7 +356,7 @@ def _resolve_spec(
     if profile_id is not None:
         p = db.get(DownloadProfile, profile_id)
         if p is None or (not p.is_builtin and p.user_id != user.id):
-            raise HTTPException(status_code=404, detail="Unknown profile")
+            raise not_found("profile")
         return p.spec, p.id
     if spec is not None:
         return spec, None
@@ -373,7 +367,7 @@ def _resolve_spec(
         .limit(1)
     ).scalar_one_or_none()
     if fallback is None:
-        raise HTTPException(status_code=400, detail="No download profile available.")
+        raise refused(400, "no_profile")
     return fallback.spec, fallback.id
 
 
@@ -484,7 +478,7 @@ def enqueue_edit(
     source file is only read, never modified, so editing a shared video is safe."""
     source_job = _accessible_job(db, user, body.source_job_id)
     if source_job.status != "done" or source_job.asset_id is None:
-        raise HTTPException(status_code=409, detail="You can only edit a finished download.")
+        raise refused(409, "edit_unfinished")
     spec = body.edit_spec
     display_name = (body.display_name or "").strip() or None
     try:
@@ -614,7 +608,7 @@ def update_download_meta(
 ) -> dict:
     """Update a download's display metadata: title, channel name + link, and extra reference URLs.
     All are display-only overrides — the on-disk file keeps its system-decided, id-bound name."""
-    job = _own_job(db, user, job_id)
+    job = owned_or_404(db, DownloadJob, job_id, user, what="download")
     sent = body.model_fields_set
     if "display_name" in sent:
         job.display_name = ((body.display_name or "").strip())[:255] or None
@@ -668,9 +662,9 @@ def redownload_download(
     if job.job_kind in ("edit", "upload"):
         # Neither has a re-fetchable source: an editor clip is derived locally, an upload IS the
         # source. Re-running yt-dlp against source_kind='upload'/'edit' would just fail.
-        raise HTTPException(status_code=409, detail="This item can't be re-downloaded.")
+        raise refused(409, "not_redownloadable")
     if job.status in ("queued", "running", "paused"):
-        raise HTTPException(status_code=409, detail="This download is still in progress.")
+        raise refused(409, "still_downloading")
     service.redownload(db, job)
     return _serialize_job(db, job)
 
@@ -699,7 +693,7 @@ def delete_download(
 def _accessible_job(db: Session, user: User, job_id: int) -> DownloadJob:
     job = db.get(DownloadJob, job_id)
     if job is None:
-        raise HTTPException(status_code=404, detail="Unknown download")
+        raise not_found("download")
     if job.user_id == user.id:
         return job
     shared = db.execute(
@@ -708,7 +702,7 @@ def _accessible_job(db: Session, user: User, job_id: int) -> DownloadJob:
         )
     ).first()
     if shared is None:
-        raise HTTPException(status_code=404, detail="Unknown download")
+        raise not_found("download")
     return job
 
 
@@ -722,10 +716,10 @@ def download_file(
     job = _accessible_job(db, user, job_id)
     asset = db.get(MediaAsset, job.asset_id) if job.asset_id else None
     if asset is None or asset.status != "ready" or not asset.rel_path:
-        raise HTTPException(status_code=409, detail="This download isn't ready.")
+        raise refused(409, "download_not_ready")
     path = storage.safe_abs_path(settings.download_root, asset.rel_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="File is no longer available.")
+        raise not_found("file")
 
     filename = storage.download_filename(
         job.display_name or asset.title or asset.source_ref, asset.container, path
@@ -764,7 +758,7 @@ def storyboard_meta(
     job = _accessible_job(db, user, job_id)
     asset = db.get(MediaAsset, job.asset_id) if job.asset_id else None
     if asset is None or asset.status != "ready" or not asset.rel_path:
-        raise HTTPException(status_code=409, detail="This download isn't ready.")
+        raise refused(409, "download_not_ready")
     meta = editmod.ensure_storyboard(asset, settings.download_root)
     if meta is None:
         return {"available": False}
@@ -785,10 +779,10 @@ def poster_image(job_id: int, user: User = Depends(require_human), db: Session =
     job = _accessible_job(db, user, job_id)
     asset = db.get(MediaAsset, job.asset_id) if job.asset_id else None
     if asset is None or not asset.poster_path:
-        raise HTTPException(status_code=404, detail="No poster.")
+        raise not_found("poster")
     path = storage.safe_abs_path(settings.download_root, asset.poster_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="No poster.")
+        raise not_found("poster")
     return FileResponse(path, media_type="image/jpeg")
 
 
@@ -799,10 +793,10 @@ def storyboard_image(
     job = _accessible_job(db, user, job_id)
     asset = db.get(MediaAsset, job.asset_id) if job.asset_id else None
     if asset is None or not asset.storyboard_path:
-        raise HTTPException(status_code=404, detail="No filmstrip.")
+        raise not_found("filmstrip")
     path = storage.safe_abs_path(settings.download_root, asset.storyboard_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="No filmstrip.")
+        raise not_found("filmstrip")
     return FileResponse(path, media_type="image/jpeg")
 
 
@@ -820,12 +814,12 @@ def share_download(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    job = _own_job(db, user, job_id)
+    job = owned_or_404(db, DownloadJob, job_id, user, what="download")
     if job.status != "done" or job.asset_id is None:
-        raise HTTPException(status_code=409, detail="Only a finished download can be shared.")
+        raise refused(409, "share_unfinished")
     target = body.email.strip().lower()
     if not target:
-        raise HTTPException(status_code=400, detail="A recipient email is required.")
+        raise refused(400, "recipient_required")
     recipient = db.execute(
         select(User).where(func.lower(User.email) == target)
     ).scalar_one_or_none()
@@ -834,7 +828,7 @@ def share_download(
     if not is_messageable_user(recipient):
         raise not_found("recipient")
     if recipient.id == user.id:
-        raise HTTPException(status_code=400, detail="That's already your download.")
+        raise refused(400, "share_own")
     exists = db.execute(
         select(DownloadShare.id).where(
             DownloadShare.job_id == job_id, DownloadShare.to_user_id == recipient.id
@@ -853,7 +847,7 @@ def share_download(
             commit=False,
         )
         db.commit()
-    return {"shared_with": recipient.email}
+    return {"ok": True, "shared_with": recipient.email}
 
 
 @router.delete("/{job_id}/share/{email}")
@@ -863,7 +857,9 @@ def unshare_download(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    _own_job(db, user, job_id)  # ownership guard (404s if not the caller's job)
+    owned_or_404(
+        db, DownloadJob, job_id, user, what="download"
+    )  # ownership guard (404s if not the caller's job)
     recipient = db.execute(
         select(User).where(func.lower(User.email) == email.strip().lower())
     ).scalar_one_or_none()
@@ -895,7 +891,7 @@ def remove_shared_with_me(
     if row is not None:
         db.delete(row)
         db.commit()
-    return {"removed": job_id}
+    return {"ok": True, "removed": job_id}
 
 
 # --- recipients (for the internal "share with a user" picker) ------------------------------
@@ -925,10 +921,10 @@ def share_recipients(
 def _own_link(db: Session, user: User, link_id: int) -> DownloadLink:
     link = db.get(DownloadLink, link_id)
     if link is None:
-        raise HTTPException(status_code=404, detail="Unknown link")
+        raise not_found("link")
     job = db.get(DownloadJob, link.job_id)
     if job is None or job.user_id != user.id:
-        raise HTTPException(status_code=404, detail="Unknown link")
+        raise not_found("link")
     return link
 
 
@@ -944,7 +940,7 @@ def _link_expiry(days: int | None) -> datetime | None:
 def list_links(
     job_id: int, user: User = Depends(require_human), db: Session = Depends(get_db)
 ) -> list[dict]:
-    _own_job(db, user, job_id)
+    owned_or_404(db, DownloadJob, job_id, user, what="download")
     rows = (
         db.execute(
             select(DownloadLink)
@@ -975,9 +971,9 @@ def create_link(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    job = _own_job(db, user, job_id)
+    job = owned_or_404(db, DownloadJob, job_id, user, what="download")
     if job.status != "done" or job.asset_id is None:
-        raise HTTPException(status_code=409, detail="Only a finished download can be shared.")
+        raise refused(409, "share_unfinished")
     pw = body.password.strip()
     link = DownloadLink(
         job_id=job_id,

backend/app/routes/feed.py

@@ -1,6 +1,6 @@
 from datetime import date, datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi import APIRouter, Depends, Query
 from pydantic import BaseModel, ConfigDict, Field
 from sqlalchemy import and_, func, or_, select
 from sqlalchemy.dialects.postgresql import insert as pg_insert
@@ -29,10 +29,11 @@ from app.models import (
     Video,
     VideoState,
 )
-from app.routes._common import get_or_404
+from app.routes._common import get_or_404, youtube_refusal, not_found
 from app.sync.videos import parse_iso8601_duration
 from app.utils import iso
 from app.youtube.client import YouTubeClient, YouTubeError
+from app.refusal import refused
 
 router = APIRouter(prefix="/api", tags=["feed"])
 
@@ -120,7 +121,7 @@ def get_feed(
             vals, cursor_id = decode_cursor(keys, cursor)
         except ValueError:
             # `from None`: the ValueError is an expected bad-input signal, not an error to chain.
-            raise HTTPException(status_code=400, detail="Invalid feed cursor") from None
+            raise refused(400, "invalid_cursor") from None
         for k, v in zip(keys, vals):
             k["value"] = v
         query = query.where(keyset_predicate(keys, cursor_id))
@@ -235,7 +236,7 @@ def set_video_state(
 ) -> dict:
     status = body.status
     if status not in VALID_STATES:
-        raise HTTPException(status_code=400, detail=f"status must be one of {VALID_STATES}")
+        raise refused(400, "invalid_status")
     get_or_404(db, Video, video_id, what="video")
 
     now = datetime.now(timezone.utc)
@@ -260,7 +261,7 @@ def set_video_state(
             # or moved this row. The state the caller asked for is the state that holds either way.
             except StaleDataError:
                 db.rollback()
-        return {"video_id": video_id, "status": "new"}
+        return {"ok": True, "video_id": video_id, "status": "new"}
 
     # watched / hidden: atomic upsert. The player marks "watched" at end-of-playback at
     # the same instant a progress checkpoint may DELETE the in-progress row; a plain
@@ -281,7 +282,7 @@ def set_video_state(
     )
     db.execute(stmt)
     db.commit()
-    return {"video_id": video_id, "status": status}
+    return {"ok": True, "video_id": video_id, "status": status}
 
 
 @router.delete("/videos/{video_id}/state")
@@ -303,7 +304,7 @@ def clear_video_state(
         # silent-ok: the row went under the delete, which is the outcome the delete wanted.
         except StaleDataError:
             db.rollback()
-    return {"video_id": video_id, "status": "new", "position_seconds": 0}
+    return {"ok": True, "video_id": video_id, "status": "new", "position_seconds": 0}
 
 
 class VideoProgressIn(BaseModel):
@@ -361,7 +362,7 @@ def set_video_progress(
             # silent-ok: exactly the race the comment above describes; the response stays true.
             except StaleDataError:
                 db.rollback()
-        return {"video_id": video_id, "position_seconds": 0}
+        return {"ok": True, "video_id": video_id, "position_seconds": 0}
 
     if row is None:
         row = VideoState(user_id=user.id, video_id=video_id)
@@ -369,7 +370,7 @@ def set_video_progress(
     row.position_seconds = position
     row.progress_updated_at = datetime.now(timezone.utc)
     db.commit()
-    return {"video_id": video_id, "position_seconds": position}
+    return {"ok": True, "video_id": video_id, "position_seconds": position}
 
 
 @router.get("/videos/{video_id}")
@@ -402,7 +403,7 @@ def get_video_detail(
     # The DB path above is free; the off-catalog YouTube lookup below spends a quota unit, so the
     # demo account can't reach it — it just sees "unknown" for a video we don't already store.
     if user.is_demo:
-        raise HTTPException(status_code=404, detail="Unknown video")
+        raise not_found("video")
 
     try:
         with (
@@ -411,9 +412,9 @@ def get_video_detail(
         ):
             items = yt.get_videos([video_id])
     except YouTubeError as exc:
-        raise HTTPException(status_code=422, detail=f"YouTube lookup failed: {exc}")
+        raise youtube_refusal(exc)
     if not items:
-        raise HTTPException(status_code=404, detail="Unknown video")
+        raise not_found("video")
 
     snippet = items[0].get("snippet", {})
     stats = items[0].get("statistics", {})

backend/app/routes/me.py

@@ -17,12 +17,16 @@ from app.auth import (
     optional_current_user,
     purge_user,
 )
-from app import diagnostics
+from app import debugsession, diagnostics
+from app.issues import gitea
 from app import email as email_mod
 from app import logs
 from app import sysconfig
 from app.db import get_db
 from app.models import Invite, User
+from app.utils import iso
+from app.refusal import refused
+from app.routes._common import not_found
 
 router = APIRouter(prefix="/api/me", tags=["me"])
 
@@ -69,7 +73,7 @@ def switch_account(
     here) are allowed, and access is re-checked in case the invite was revoked since."""
     target = body.user_id
     if target not in (request.session.get("account_ids") or []):
-        raise HTTPException(status_code=403, detail="Not an account you've signed into here.")
+        raise refused(403, "not_your_account")
     # An account `_session_user` would refuse — gone, deactivated, suspended, or its session revoked — is
     # refused here too, and dropped from the switch list the way `_session_user` drops it. Made the session
     # default instead, the next request's current_user would refuse it as the DEFAULT and clear the whole
@@ -77,22 +81,20 @@ def switch_account(
     u = db.get(User, target)
     if u is None:
         drop_from_wallet(request.session, target)
-        raise HTTPException(status_code=404, detail="That account no longer exists.")
+        raise not_found("account")
     if not is_allowed(db, u.email):
-        raise HTTPException(status_code=403, detail="That account no longer has access.")
+        raise refused(403, "account_no_access")
     if not u.is_active:
         drop_from_wallet(request.session, target)
-        raise HTTPException(status_code=403, detail="That account no longer has access.")
+        raise refused(403, "account_no_access")
     if u.is_suspended:
         drop_from_wallet(request.session, target)
-        raise HTTPException(status_code=403, detail="That account is suspended.")
+        raise refused(403, "account_suspended")
     # Revoked: a password reset/change or "log out everywhere" bumped the account's epoch.
     epochs = request.session.get("epochs") or {}
     if int(epochs.get(str(target), 0)) != (u.session_epoch or 0):
         drop_from_wallet(request.session, target)
-        raise HTTPException(
-            status_code=403, detail="That account was signed out elsewhere — sign in again."
-        )
+        raise refused(403, "account_signed_out")
     request.session["user_id"] = target
     return {"ok": True, "user_id": target}
 
@@ -138,6 +140,9 @@ def get_me(
             user.google_email if user.google_email and user.google_email != user.email else None
         ),
         "has_password": user.password_hash is not None,
+        # The account's latest sign-in on any device — shown in Settings → Account, so a sign-in the
+        # user does not recognise is something they can see (null: none since 0.88, or the demo).
+        "last_login_at": iso(user.last_login_at),
         # Instance-wide: whether Google sign-in / YouTube connect is available at all (the UI hides
         # YouTube-access affordances and the onboarding nudge when it isn't configured).
         "google_enabled": google_enabled(db),
@@ -154,9 +159,18 @@ def get_me(
         # The consented diagnostics level in force and when it lapses (E22 S5). The client applies
         # it to its own log and streams that log while it is raised.
         "diagnostics": diagnostics.state(db, user),
+        # The live debug session, if one is recording (E16) — a reload resumes it.
+        "debug_session": _live_session(db, user),
+        # Where a bug report goes (E16 S4): the tracker's repository, or None — download only.
+        "issues": gitea.target(db),
     }
 
 
+def _live_session(db: Session, user: User) -> dict | None:
+    session = debugsession.open_session(db, user)
+    return None if session is None else debugsession.view(db, session)
+
+
 @router.delete("/account")
 def delete_my_account(
     request: Request,
@@ -177,10 +191,7 @@ def delete_my_account(
     if user.is_demo:
         raise HTTPException(status_code=403, detail={"code": "demo", "reason": "delete_account"})
     if user.role == "admin" and count_admins(db) <= 1:
-        raise HTTPException(
-            status_code=400,
-            detail="You're the only admin — promote another admin before deleting your account.",
-        )
+        raise refused(400, "only_admin_delete")
     user_id = user.id
     # Full erasure (cascades) + access-request cleanup + Google-grant revocation; shared with the
     # admin delete path. Capture the id first — `user` is detached once purge_user deletes the row.
@@ -213,7 +224,7 @@ def update_preferences(
     user.preferences = merged
     db.add(user)
     db.commit()
-    return {"preferences": merged}
+    return {"ok": True, "preferences": merged}
 
 
 class DiagnosticsIn(BaseModel):

backend/app/routes/messages.py

@@ -16,7 +16,7 @@ routing and unread counts.
 
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException, WebSocket, WebSocketDisconnect
+from fastapi import APIRouter, Depends, WebSocket, WebSocketDisconnect
 from pydantic import BaseModel
 from sqlalchemy import and_, case, delete, func, or_, select
 from sqlalchemy.orm import Session
@@ -29,6 +29,8 @@ from app.realtime import manager
 from app.security import verify_password
 from app.userscope import is_messageable_user, messageable_clauses
 from app.utils import iso
+from app.refusal import refused
+from app.routes._common import not_found
 
 router = APIRouter(prefix="/api/messages", tags=["messages"])
 
@@ -152,7 +154,7 @@ def setup_keys(
     """Store this user's public key + passphrase-wrapped private key. Set-once: changing the
     key would orphan every existing conversation key, so re-setup is rejected here."""
     if db.get(MessageKey, user.id) is not None:
-        raise HTTPException(status_code=409, detail="Secure messaging is already set up.")
+        raise refused(409, "messaging_set_up")
     db.add(
         MessageKey(
             user_id=user.id,
@@ -164,7 +166,7 @@ def setup_keys(
         )
     )
     db.commit()
-    return {"configured": True}
+    return {"ok": True, "configured": True}
 
 
 @router.post("/keys/reset")
@@ -185,11 +187,11 @@ def reset_keys(
     less (Google-only) account has nothing to re-verify, so it relies on its live session plus the
     client-side danger confirmation."""
     if not _reset_key_limiter.allow(str(user.id)):
-        raise HTTPException(status_code=429, detail="Too many attempts. Try again shortly.")
+        raise refused(429, "too_many_attempts")
     if user.password_hash and not verify_password(
         payload.current_password or "", user.password_hash
     ):
-        raise HTTPException(status_code=403, detail="Current password is incorrect.")
+        raise refused(403, "wrong_password")
     # Delete the now-dead ciphertext first (both directions), then the wrapped keypair itself so a
     # fresh setup is allowed. Order doesn't matter (no FK between them), but do it in one commit.
     db.execute(
@@ -202,7 +204,7 @@ def reset_keys(
     if key is not None:
         db.delete(key)
     db.commit()
-    return {"configured": False}
+    return {"ok": True, "configured": False}
 
 
 @router.get("/keys/{user_id}")
@@ -223,10 +225,10 @@ def public_key(
     p = db.get(User, user_id)
     has_history = db.scalar(select(Message.id).where(cond).limit(1))
     if p is None or (not is_messageable_user(p) and not has_history):
-        raise HTTPException(status_code=404, detail="User not found")
+        raise not_found("user")
     k = db.get(MessageKey, user_id)
     if k is None:
-        raise HTTPException(status_code=404, detail="That member hasn't set up messaging yet.")
+        raise refused(404, "no_messaging")
     return {"user_id": user_id, "public_key": k.public_key}
 
 
@@ -344,7 +346,7 @@ def get_thread(
         # still opens). Otherwise the same 404 as a non-existent id → no enumeration oracle.
         has_history = db.scalar(select(Message.id).where(cond).limit(1))
         if p is None or (not is_messageable_user(p) and not has_history):
-            raise HTTPException(status_code=404, detail="User not found")
+            raise not_found("user")
         partner = _serialize_user(p)
     msgs = (
         db.execute(select(Message).where(cond).order_by(Message.created_at.asc())).scalars().all()
@@ -374,20 +376,20 @@ def send_message(
     """Send an end-to-end-encrypted message. The server stores only the ciphertext the client
     produced, then pushes it live to the recipient (and the sender's other devices)."""
     if not _send_limiter.allow(f"msg:{user.id}"):
-        raise HTTPException(status_code=429, detail="Too many messages — slow down a moment.")
+        raise refused(429, "message_rate")
     ct = (payload.ciphertext or "").strip()
     iv = (payload.iv or "").strip()
     if not ct or not iv:
-        raise HTTPException(status_code=400, detail="Message is empty.")
+        raise refused(400, "message_empty")
     if len(ct) > MAX_CIPHERTEXT:
-        raise HTTPException(status_code=400, detail="Message is too long.")
+        raise refused(400, "message_too_long")
     if payload.recipient_id == user.id:
-        raise HTTPException(status_code=400, detail="You can't message yourself.")
+        raise refused(400, "message_self")
     recipient = db.get(User, payload.recipient_id)
     if not is_messageable_user(recipient):
-        raise HTTPException(status_code=404, detail="Recipient not available.")
+        raise not_found("recipient")
     if db.get(MessageKey, recipient.id) is None:
-        raise HTTPException(status_code=404, detail="That member hasn't set up messaging yet.")
+        raise refused(404, "no_messaging")
     m = Message(kind="user", sender_id=user.id, recipient_id=recipient.id, ciphertext=ct, iv=iv)
     db.add(m)
     db.commit()

backend/app/routes/notifications.py

@@ -5,7 +5,7 @@ All endpoints use `current_user` (not `require_human`): notifications and their
 state are personal UI state with no quota or YouTube involvement, so the shared demo account
 manages its own inbox normally."""
 
-from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi import APIRouter, Depends, Query
 from sqlalchemy import func, select, update
 from sqlalchemy.orm import Session
 
@@ -14,6 +14,7 @@ from app.db import get_db
 from app.models import Notification, User
 from app.notifications import trim_read
 from app.utils import iso
+from app.routes._common import owned_or_404
 
 router = APIRouter(prefix="/api/me/notifications", tags=["notifications"])
 
@@ -72,20 +73,13 @@ def unread_count(user: User = Depends(current_user), db: Session = Depends(get_d
     return {"count": count or 0}
 
 
-def _owned(db: Session, notification_id: int, user: User) -> Notification:
-    n = db.get(Notification, notification_id)
-    if n is None or n.user_id != user.id:
-        raise HTTPException(status_code=404, detail="Notification not found")
-    return n
-
-
 @router.post("/{notification_id}/read")
 def mark_read(
     notification_id: int,
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    n = _owned(db, notification_id, user)
+    n = owned_or_404(db, Notification, notification_id, user, what="notification")
     n.read = True
     db.commit()
     trim_read(db, user.id)
@@ -110,7 +104,7 @@ def dismiss(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    n = _owned(db, notification_id, user)
+    n = owned_or_404(db, Notification, notification_id, user, what="notification")
     # Dismiss implies read (it no longer counts toward the unread badge).
     n.dismissed = True
     n.read = True

backend/app/routes/playlists.py

@@ -3,11 +3,10 @@ CRUD (create / rename / delete, add / remove / reorder items) plus YouTube two-w
 mirror the user's own YouTube playlists in (`/sync-youtube`) and push/revert local edits back
 out (`/{id}/push-plan`, `/{id}/revert-youtube`), behind the optional write scope."""
 
-from datetime import datetime, timezone
-
 from fastapi import APIRouter, Depends, HTTPException
 from pydantic import BaseModel
 from sqlalchemy import func, select, and_
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import Session, aliased
 
 from app import quota
@@ -23,7 +22,7 @@ from app.sync.playlists import (
     sync_user_playlists,
 )
 from app.ratelimit import RateLimiter
-from app.routes._common import get_or_404, owned_or_404
+from app.routes._common import get_or_404, owned_or_404, youtube_refusal
 from app.youtube.client import YouTubeClient, YouTubeError
 
 router = APIRouter(prefix="/api/playlists", tags=["playlists"])
@@ -48,10 +47,6 @@ def _check_pull_cooldown(user: User) -> None:
         raise HTTPException(status_code=429, detail={"code": "sync_cooldown"})
 
 
-def _own_playlist(db: Session, user: User, playlist_id: int) -> Playlist:
-    return owned_or_404(db, Playlist, playlist_id, user, what="playlist")
-
-
 def _refused(status: int, reason: str) -> HTTPException:
     """A playlist action the server refuses, as a reason the UI translates
     (`playlists.errors.<reason>`) — a bare English detail reached the Hungarian UI verbatim."""
@@ -64,8 +59,11 @@ def _touch(pl: Playlist) -> None:
     `UpdatedAtMixin`'s `onupdate` fires on an UPDATE of the PLAYLIST row, and add / remove /
     reorder / move write the item rows instead — so without this the rail's "recently changed"
     sort would only ever see renames. The assignment is what makes the column mean "last time
-    this list changed", which is what the rail promises the reader."""
-    pl.updated_at = datetime.now(timezone.utc)
+    this list changed", which is what the rail promises the reader.
+
+    The DATABASE's clock, like the mixin's own `onupdate`: one sort key written from two clocks
+    (this process's and Postgres's) could order a rename and an item edit the wrong way round."""
+    pl.updated_at = func.now()
 
 
 def _next_playlist_position(db: Session, user_id: int) -> int:
@@ -108,7 +106,7 @@ def _add_item(db: Session, pl: Playlist, video_id: str, *, mark_dirty: bool) ->
     if mark_dirty:
         recompute_dirty(db, pl)
     _touch(pl)
-    db.commit()
+    db.flush()  # the handler commits (CLAUDE.md: helpers flush)
     return True
 
 
@@ -126,7 +124,7 @@ def _remove_item(db: Session, pl: Playlist, video_id: str, *, mark_dirty: bool)
     if mark_dirty:
         recompute_dirty(db, pl)
     _touch(pl)
-    db.commit()
+    db.flush()  # the handler commits (CLAUDE.md: helpers flush)
     return True
 
 
@@ -280,7 +278,7 @@ def _watch_later(db: Session, user: User) -> Playlist:
             position=_next_playlist_position(db, user.id),
         )
         db.add(pl)
-        db.commit()
+        db.flush()  # the id, for the item the caller adds next; the handler commits
     return pl
 
 
@@ -295,7 +293,8 @@ def add_watch_later(
     get_or_404(db, Video, video_id, what="video")
     pl = _watch_later(db, user)
     _add_item(db, pl, video_id, mark_dirty=False)
-    return {"saved": True, "playlist_id": pl.id}
+    db.commit()
+    return {"ok": True, "saved": True, "playlist_id": pl.id}
 
 
 @router.delete("/watch-later/{video_id}")
@@ -309,7 +308,8 @@ def remove_watch_later(
     )
     if pl is not None:
         _remove_item(db, pl, video_id, mark_dirty=False)
-    return {"saved": False}
+        db.commit()
+    return {"ok": True, "saved": False}
 
 
 @router.post("/sync-youtube")
@@ -322,8 +322,12 @@ def sync_youtube(
     if not has_read_scope(user):
         raise _refused(403, "youtube_read_scope")
     _check_pull_cooldown(user)
-    with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_PULL):
-        return sync_user_playlists(db, user)
+    try:
+        with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_PULL):
+            return {"ok": True, **sync_user_playlists(db, user)}
+    except YouTubeError as exc:
+        db.rollback()
+        raise youtube_refusal(exc)
 
 
 @router.post("/{playlist_id}/revert-youtube")
@@ -335,7 +339,7 @@ def revert_youtube(
     """Reset one YouTube-linked playlist to its current YouTube state, discarding local
     edits (and clearing the dirty flag). The user-facing 'undo all my changes' for a list
     once the in-session undo history is gone."""
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     if not pl.yt_playlist_id:
         raise _refused(400, "not_on_youtube")
     if not has_read_scope(user):
@@ -343,16 +347,16 @@ def revert_youtube(
     _check_pull_cooldown(user)
     try:
         with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_PULL):
-            return repull_playlist(db, user, pl)
-    except YouTubeError:
+            return {"ok": True, **repull_playlist(db, user, pl)}
+    except YouTubeError as exc:
         db.rollback()
-        raise _refused(422, "youtube_failed")
+        raise youtube_refusal(exc)
 
 
 def _pushable(db: Session, user: User, playlist_id: int) -> Playlist:
     """A local playlist the user may push to YouTube (create or update). The built-in
     Watch later and read-only YouTube mirrors are never pushable."""
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     if pl.kind == "watch_later":
         raise _refused(400, "watch_later_not_pushable")
     return pl
@@ -371,8 +375,8 @@ def push_plan(
     try:
         with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_PUSH):
             plan = plan_merge(db, user, pl)
-    except YouTubeError:
-        raise _refused(422, "youtube_failed")
+    except YouTubeError as exc:
+        raise youtube_refusal(exc)
     plan["remaining_today"] = quota.remaining_today(db)
     plan["affordable"] = plan["units_estimate"] <= plan["remaining_today"]
     return plan
@@ -403,10 +407,10 @@ def push(
             plan = plan_merge(db, user, pl, live=live)
             if plan["units_estimate"] > quota.remaining_today(db):
                 raise _refused(429, "quota_exceeded")
-            return merge_playlist(db, user, pl, live=live)
-    except YouTubeError:
+            return {"ok": True, **merge_playlist(db, user, pl, live=live)}
+    except YouTubeError as exc:
         db.rollback()
-        raise _refused(422, "youtube_failed")
+        raise youtube_refusal(exc)
 
 
 @router.get("/{playlist_id}")
@@ -415,7 +419,7 @@ def get_playlist(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     state = aliased(VideoState)
     rows = db.execute(
         select(*feed_columns(user, state))
@@ -447,7 +451,7 @@ def rename_playlist(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     if "name" in body.model_fields_set:
         name = (body.name or "").strip()
         if not name:
@@ -484,7 +488,7 @@ def delete_playlist(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     if pl.kind == "watch_later":
         raise _refused(400, "watch_later_undeletable")
     if on_youtube:
@@ -496,8 +500,8 @@ def delete_playlist(
             with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_DELETE):
                 with YouTubeClient(db, user) as yt:
                     yt.delete_playlist(pl.yt_playlist_id)
-        except YouTubeError:
-            raise _refused(422, "youtube_failed")
+        except YouTubeError as exc:
+            raise youtube_refusal(exc)
     db.delete(pl)  # items cascade
     db.commit()
     return {"deleted": playlist_id}
@@ -510,11 +514,12 @@ def add_item(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     video_id = body.video_id
     get_or_404(db, Video, video_id, what="video")
     _add_item(db, pl, video_id, mark_dirty=True)
-    return {"playlist_id": pl.id, "video_id": video_id}
+    db.commit()
+    return {"ok": True, "playlist_id": pl.id, "video_id": video_id}
 
 
 @router.delete("/{playlist_id}/items/{video_id}")
@@ -524,9 +529,10 @@ def remove_item(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     _remove_item(db, pl, video_id, mark_dirty=True)
-    return {"playlist_id": pl.id, "video_id": video_id}
+    db.commit()
+    return {"ok": True, "playlist_id": pl.id, "video_id": video_id}
 
 
 class MoveItemIn(BaseModel):
@@ -548,7 +554,7 @@ def move_item(
     exactly the kind of half-applied state this codebase treats as a bug rather than an edge
     case. Idempotent: if the video is already in the target, the source row is simply dropped
     (moving into a list that already has it is a removal, not a duplicate)."""
-    src = _own_playlist(db, user, playlist_id)
+    src = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     # Its own reason: "this playlist doesn't exist any more" about a TARGET that is gone was read as
     # the list on screen — which is still there.
     dst = owned_or_404(db, Playlist, body.target_playlist_id, user, what="move_target")
@@ -571,19 +577,33 @@ def move_item(
             PlaylistItem.playlist_id == dst.id, PlaylistItem.video_id == video_id
         )
     )
-    if already is not None:
-        db.delete(item)  # the uq_playlist_video constraint would reject a second row anyway
-    else:
+    dst_changed = False
+    if already is None:
         # Re-parent the existing row rather than delete+insert: `added_at` ("when I saved this")
-        # survives the move, and there is no window where the video belongs to neither list.
-        item.playlist_id = dst.id
-        item.position = _next_item_position(db, dst.id)
-    # Both sides changed, so both get the dirty recompute and the timestamp — the asymmetric
-    # version of this (touching only the source) is the recurring smell CLAUDE.md warns about.
+        # survives the move, and there is no window where the video belongs to neither list. The
+        # check above is not a lock: a second tab's add or the scheduler's YouTube merge can insert
+        # the same (playlist, video) in between, and uq_playlist_video then refuses the re-parent.
+        # That is the already-present outcome arriving late, not a failure — answer it the same way
+        # instead of a raw 500.
+        try:
+            with db.begin_nested():
+                item.playlist_id = dst.id
+                item.position = _next_item_position(db, dst.id)
+                db.flush()
+            dst_changed = True
+        # silent-ok: the conflict IS the answer — the target already holds the video, which is the
+        # idempotent outcome; the savepoint put the row back in the source list, dropped below.
+        except IntegrityError:
+            pass
+    if not dst_changed:
+        db.delete(item)
+    # The source always changed; the target only when the row landed in it. `_touch` on a target
+    # that already had the video promoted an untouched list in the rail's "recently changed" sort.
     recompute_dirty(db, src)
-    recompute_dirty(db, dst)
     _touch(src)
-    _touch(dst)
+    if dst_changed:
+        recompute_dirty(db, dst)
+        _touch(dst)
     db.commit()
     return {"ok": True, "from_playlist_id": src.id, "to_playlist_id": dst.id, "video_id": video_id}
 
@@ -599,7 +619,7 @@ def reorder_items(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist(db, user, playlist_id)
+    pl = owned_or_404(db, Playlist, playlist_id, user, what="playlist")
     order = body.video_ids
     items = {
         it.video_id: it
@@ -625,4 +645,4 @@ def reorder_items(
     recompute_dirty(db, pl)
     _touch(pl)
     db.commit()
-    return {"playlist_id": pl.id, "count": pos}
+    return {"ok": True, "playlist_id": pl.id, "count": pos}

backend/app/routes/plex/_shared.py

@@ -1,11 +1,11 @@
 """Shared helpers, serializers and constants for the plex route package."""
 
-from fastapi import HTTPException
 from sqlalchemy.orm import Session
 
 from app import logs
 from app.models import PlexItem
 from app.plex.lookups import by_rating_key
+from app.routes._common import not_found
 
 log = logs.get_logger(__name__)
 
@@ -13,7 +13,7 @@ log = logs.get_logger(__name__)
 def item_or_404(db: Session, rating_key: str) -> PlexItem:
     it = by_rating_key(db, PlexItem, rating_key)
     if it is None:
-        raise HTTPException(status_code=404, detail="Unknown Plex item")
+        raise not_found("plex_item")
     return it
 
 

backend/app/routes/plex/admin.py

@@ -2,12 +2,12 @@
 
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.auth import admin_user, current_user
 from app.db import get_db
 from app.models import (
@@ -20,6 +20,9 @@ from app.plex import sync as plex_sync
 from app.plex import watch_sync as plex_watch
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.utils import iso
+from app.refusal import refused
+
+log = logs.get_logger(__name__)
 
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 
@@ -35,10 +38,15 @@ def test_connection(_: User = Depends(admin_user), db: Session = Depends(get_db)
             info = plex.server_info()
             sections = plex.sections()
             media_check = _media_check(db, plex, sections)
-    except PlexNotConfigured as e:
-        raise HTTPException(status_code=400, detail=str(e))
+    except PlexNotConfigured:
+        raise refused(400, "plex_not_configured") from None
     except PlexError as e:
-        raise HTTPException(status_code=422, detail=f"Plex connection failed: {e}")
+        # What the upstream said is for the log, not the toast: it can quote the server URL back.
+        log.warning(
+            "the Plex connection test failed",
+            extra=logs.event("plex.admin.connection_failed", reason=type(e).__name__, error=str(e)),
+        )
+        raise refused(422, "plex_unreachable") from None
     return {
         "ok": True,
         "server_name": info.get("friendlyName") or info.get("title1") or "Plex",
@@ -95,7 +103,7 @@ def _media_check(db: Session, plex: PlexClient, sections: list[dict]) -> dict:
 def trigger_sync(_: User = Depends(admin_user), db: Session = Depends(get_db)) -> dict:
     """Admin: mirror the enabled Plex sections into the local catalog. Synchronous (can take a
     while on a large library); a background/scheduled sync also runs periodically."""
-    return plex_sync.sync(db)
+    return {"ok": True, **plex_sync.sync(db)}
 
 
 def _link_dict(link: PlexLink | None) -> dict:
@@ -129,7 +137,7 @@ def watch_link_set(
     admin token, so no separate Plex login. Enabling it for the first time runs the one-time
     "Plex is master" import immediately so the owner's existing Plex history shows up in Siftlode."""
     if not sysconfig.get_bool(db, "plex_enabled"):
-        raise HTTPException(status_code=409, detail="The Plex module is disabled.")
+        raise refused(409, "plex_disabled")
     enabled = body.enabled
     link = db.execute(select(PlexLink).where(PlexLink.user_id == user.id)).scalars().first()
     if link is None:
@@ -141,7 +149,7 @@ def watch_link_set(
     result: dict = {}
     if enabled and not link.initial_import_done:
         result = plex_watch.import_owner_watch_state(db, link)
-    return {**_link_dict(link), "import": result or None}
+    return {"ok": True, **_link_dict(link), "import": result or None}
 
 
 @router.post("/watch/import")
@@ -150,6 +158,6 @@ def watch_import_now(user: User = Depends(admin_user), db: Session = Depends(get
     intersection; Siftlode-only states are preserved. Idempotent."""
     link = db.execute(select(PlexLink).where(PlexLink.user_id == user.id)).scalars().first()
     if link is None or not link.sync_enabled:
-        raise HTTPException(status_code=409, detail="Enable Plex watch-sync first.")
+        raise refused(409, "watch_sync_off")
     result = plex_watch.import_owner_watch_state(db, link)
-    return {**_link_dict(link), "import": result}
+    return {"ok": True, **_link_dict(link), "import": result}

backend/app/routes/plex/collections.py

@@ -9,6 +9,7 @@ from pydantic import BaseModel
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
+from app import logs
 from app.auth import admin_user, current_user
 from app.db import get_db
 from app.models import (
@@ -24,7 +25,12 @@ from app.plex import sync as plex_sync
 from app.plex.cards import movie_card, show_card
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.plex.lookups import by_rating_key
-from app.plex.query import content_libs, like_escape, runtime_by_key, top_art_keys
+from app.plex.query import content_libs, runtime_by_key, top_art_keys
+from app.utils import like_escape
+from app.refusal import refused
+from app.routes._common import not_found
+
+log = logs.get_logger(__name__)
 
 # The most-restrictive → least ordering used to pick a collection's effective content rating from its
 # members (Plex shows one cert on the collection; we don't store it, so derive it).
@@ -233,7 +239,7 @@ def collection_detail(
     endpoints below."""
     col = by_rating_key(db, PlexCollection, rating_key)
     if col is None:
-        raise HTTPException(status_code=404, detail="Unknown collection")
+        raise not_found("collection")
     movies = (
         db.execute(
             select(PlexItem)
@@ -324,9 +330,9 @@ def collection_detail(
 def _editable_collection_or_403(db: Session, rating_key: str) -> PlexCollection:
     col = by_rating_key(db, PlexCollection, rating_key)
     if col is None:
-        raise HTTPException(status_code=404, detail="Unknown collection")
+        raise not_found("collection")
     if not _collection_editable(col):
-        raise HTTPException(status_code=403, detail="This collection is read-only")
+        raise refused(403, "collection_read_only")
     return col
 
 
@@ -361,14 +367,13 @@ def _write_or_pending_error(wrote: bool, e: Exception) -> HTTPException:
     Both use 422, NOT a 5xx: the frontend treats 502/503/504 as "gateway unreachable" and raises a
     sticky offline banner (see api/core.ts RETRIABLE_GATEWAY). A 422 surfaces the detail as an ordinary
     action-error toast, which is what both of these are — the app answered, it didn't go unreachable."""
-    if wrote:
-        detail = (
-            "Collection updated in Plex, but refreshing the local copy failed; "
-            f"it will reconcile on the next sync ({e})"
-        )
-    else:
-        detail = f"Plex write failed: {e}"
-    return HTTPException(status_code=422, detail=detail)
+    log.warning(
+        "a Plex collection write did not settle",
+        extra=logs.event(
+            "plex.collections.write_failed", wrote=wrote, reason=type(e).__name__, error=str(e)
+        ),
+    )
+    return refused(422, "collection_pending_sync") if wrote else refused(422, "plex_write_failed")
 
 
 class CreateCollectionIn(BaseModel):
@@ -388,7 +393,7 @@ def create_collection(
     title = body.title.strip()
     seed = body.item_rating_key
     if not title or not seed:
-        raise HTTPException(status_code=400, detail="title and item_rating_key are required")
+        raise refused(400, "collection_fields_required")
     if library:
         lib = (
             db.execute(select(PlexLibrary).where(PlexLibrary.plex_key == library)).scalars().first()
@@ -398,7 +403,7 @@ def create_collection(
         seed_item = by_rating_key(db, PlexItem, seed) or by_rating_key(db, PlexShow, seed)
         lib = db.get(PlexLibrary, seed_item.library_id) if seed_item else None
     if lib is None:
-        raise HTTPException(status_code=404, detail="Unknown library")
+        raise not_found("library")
     _reject_duplicate_name(db, lib.id, title)
     wrote = False
     try:
@@ -472,7 +477,7 @@ def collection_rename(
     col = _editable_collection_or_403(db, rating_key)
     title = body.title.strip()
     if not title:
-        raise HTTPException(status_code=400, detail="title is required")
+        raise refused(400, "title_required")
     _reject_duplicate_name(db, col.library_id, title, exclude_rk=rating_key)
     lib = db.get(PlexLibrary, col.library_id)
     wrote = False
@@ -501,7 +506,7 @@ def collection_delete(
         db.commit()
     except (PlexError, PlexNotConfigured) as e:
         db.rollback()
-        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
+        raise _write_or_pending_error(False, e) from None
     return {"deleted": rating_key}
 
 
@@ -520,13 +525,10 @@ def collection_set_editable(
     (IMDb/TMDb/…) can never be made editable — they're regenerated outside Plex."""
     col = by_rating_key(db, PlexCollection, rating_key)
     if col is None:
-        raise HTTPException(status_code=404, detail="Unknown collection")
+        raise not_found("collection")
     want = body.editable
     if want and (col.smart or _collection_source(col) != "collection"):
-        raise HTTPException(
-            status_code=400,
-            detail="Smart / auto-list collections can't be made editable",
-        )
+        raise refused(400, "collection_smart")
     col.editable = want
     db.commit()
     return _collection_card(col)

backend/app/routes/plex/detail.py

@@ -5,7 +5,7 @@ import time
 from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
@@ -30,6 +30,7 @@ from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.plex.lookups import by_rating_key
 from app.routes.plex._shared import _norm_lang, item_or_404
 from app.routes.plex.collections import _collection_source
+from app.routes._common import not_found
 
 log = logs.get_logger(__name__)
 
@@ -109,7 +110,7 @@ def show_detail(
     hu = _norm_lang(lang) == "hu"
     sh = by_rating_key(db, PlexShow, rating_key)
     if sh is None:
-        raise HTTPException(status_code=404, detail="Unknown Plex show")
+        raise not_found("show")
     seasons = (
         db.execute(
             select(PlexSeason)

backend/app/routes/plex/discover.py

@@ -32,12 +32,12 @@ from app.plex.query import (
     meta_filter_conds,
     top_art_keys,
 )
+from app.discover.queries import RAIL_LIMIT
 from app.plex.tmdb import resolve_recs
 from app.routes.plex._shared import _norm_lang
 
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 
-RAIL_LIMIT = 20
 GENRE_TILES = 12
 SURPRISE_PER_KIND = 3  # Surprise-me: at most this many movies + this many shows (6 total)
 

backend/app/routes/plex/playback.py

@@ -17,7 +17,8 @@ from fastapi import (
 )
 from fastapi.responses import FileResponse
 from pydantic import BaseModel, ConfigDict, Field
-from sqlalchemy import select
+from sqlalchemy import select, update
+from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.orm import Session
 
 from app.auth import current_user, resolved_user_id
@@ -38,6 +39,8 @@ from app.plex import stream as plex_stream
 from app.plex import watch_sync as plex_watch
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.routes.plex._shared import item_or_404
+from app.refusal import refused
+from app.routes._common import not_found
 
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 
@@ -48,7 +51,7 @@ def _require_session(request: Request) -> int:
     low-sensitivity; a valid session is enough."""
     uid, _ = resolved_user_id(request)
     if not uid:
-        raise HTTPException(status_code=401, detail="Not authenticated")
+        raise refused(401, "not_authenticated")
     return uid
 
 
@@ -77,15 +80,17 @@ def image(rating_key: str, request: Request, variant: str = "thumb") -> Response
         with SessionLocal() as db:
             key = imgcache.key_for(db, str(rating_key), v)
             if not key:
-                raise HTTPException(status_code=404, detail="No image")
+                raise not_found("image")
             plex = PlexClient(db)  # reads base URL + token now; the fetch below needs no DB
-    except PlexNotConfigured as e:
-        raise HTTPException(status_code=400, detail=str(e))
+    except PlexNotConfigured:
+        raise refused(400, "plex_not_configured") from None
     try:
         with plex:
             data, ct = plex.image_bytes(key, w, h)
-    except PlexError as e:
-        raise HTTPException(status_code=502, detail=f"Plex image fetch failed: {e}")
+    # silent-ok: a byte proxy for an <img>; the browser shows the placeholder and no reader sees the
+    # detail — the 502 is the whole answer, as for the person-image proxy below.
+    except PlexError:
+        raise refused(502, "image_fetch_failed") from None
     imgcache.write(cache_key, data, ct)
     return imgcache.response(data, ct)
 
@@ -120,7 +125,7 @@ def subtitle_status(
 
     `at` is the viewer's absolute position: the extractor windows around it, so what gets read first
     is the part actually about to be watched."""
-    return subtitles.ensure(rating_key, sub_ord, at)
+    return subtitles.ensure(rating_key, sub_ord, at, viewer=user.id)
 
 
 @router.get("/subtitle/{rating_key}/{sub_ord}")
@@ -213,7 +218,7 @@ def person_image(u: str, request: Request) -> Response:
     Signed-session auth (no DB) so it, like /image, never holds a pool connection during the fetch."""
     _require_session(request)
     if not u.startswith(plex_people.PERSON_IMG_HOST):
-        raise HTTPException(status_code=400, detail="Unsupported image host")
+        raise refused(400, "image_host")
     cache_key = "person_" + hashlib.sha1(u.encode()).hexdigest()
     hit = imgcache.read(cache_key)
     if hit:
@@ -223,7 +228,7 @@ def person_image(u: str, request: Request) -> Response:
             r = c.get(u)
             r.raise_for_status()
     except httpx.HTTPError:
-        raise HTTPException(status_code=502, detail="Image fetch failed")
+        raise refused(502, "image_fetch_failed")
     ct = r.headers.get("content-type", "image/jpeg")
     imgcache.write(cache_key, r.content, ct)
     return imgcache.response(r.content, ct)
@@ -295,6 +300,37 @@ def _push_watch(
     )
 
 
+def _mark_finished(db: Session, user_id: int, item_id: int, now: datetime) -> bool:
+    """Mark the item watched (position cleared) and say whether THIS call made it so. Two near-end
+    checkpoints arrive together routinely (the 10 s tick and the debounced `seeked` flush), and a
+    read-then-write let both see "not watched" and both scrobble. The transition is decided by the
+    write itself: an insert that did not conflict, or an update conditional on the old status —
+    under READ COMMITTED the second writer re-reads the committed row and matches nothing."""
+    values = {
+        "status": "watched",
+        "watched_at": now,
+        "position_seconds": 0,
+        "progress_updated_at": now,
+        "synced_to_plex": False,
+    }
+    inserted = db.execute(
+        pg_insert(PlexState)
+        .values(user_id=user_id, item_id=item_id, **values)
+        .on_conflict_do_nothing(constraint="uq_plex_user_item")
+        .returning(PlexState.id)
+    ).first()
+    if inserted is not None:
+        return True
+    mine = (PlexState.user_id == user_id) & (PlexState.item_id == item_id)
+    if db.execute(
+        update(PlexState).where(mine, PlexState.status != "watched").values(values)
+    ).rowcount:
+        return True
+    # Already watched: a re-finish still restamps the row, as it always did — just no scrobble.
+    db.execute(update(PlexState).where(mine).values(values))
+    return False
+
+
 class ItemProgressIn(BaseModel):
     # Finite only: JSON parsing here accepts `Infinity`/`NaN`, and the handler's `int()` turned
     # one into a 500.
@@ -330,11 +366,27 @@ def item_progress(
     # finish latch is up, or before the first position is known. Those are the states in which
     # reaping is the right answer anyway, and a viewer who scrubs back into a reaped session gets
     # the same 404 → reclaim the player already handles.
-    plex_stream.touch_session(str(rating_key))
+    plex_stream.touch_session(user.id, str(rating_key))
     position = max(0, int(body.position_seconds))
     duration = int(body.duration_seconds)
     final = body.final
     now = datetime.now(timezone.utc)
+    near_end = duration > 0 and position > duration - _FINISH_MARGIN_S
+    if near_end:
+        flipped = _mark_finished(db, user.id, it.id, now)
+        # The finish supersedes every resume push still in flight for this item: stamping it as the
+        # latest push makes `_resume_push_superseded` drop them. Popping the entry instead (to keep
+        # the map small) removed the very guard, and an older resume push could then land at Plex
+        # AFTER the scrobble and revive a resume point on a watched item. Eviction bounds the map.
+        with _push_throttle_lock:
+            _last_push_at[(user.id, it.id)] = now
+        db.commit()
+        # Only the checkpoint that flipped the row scrobbles: a later checkpoint of the same finished
+        # item — or a second one racing this one — would otherwise bump Plex's viewCount again.
+        if flipped:
+            _push_watch(background, db, user.id, it.id, rating_key, "watched")
+        return {"ok": True, "status": "watched", "position_seconds": 0}
+
     st = (
         db.execute(
             select(PlexState).where(PlexState.user_id == user.id, PlexState.item_id == it.id)
@@ -342,28 +394,6 @@ def item_progress(
         .scalars()
         .first()
     )
-    was_watched = st is not None and st.status == "watched"
-
-    near_end = duration > 0 and position > duration - _FINISH_MARGIN_S
-    if near_end:
-        if st is None:
-            st = PlexState(user_id=user.id, item_id=it.id)
-            db.add(st)
-        st.status = "watched"
-        st.watched_at = now
-        st.position_seconds = 0
-        st.progress_updated_at = now
-        st.synced_to_plex = False
-        # Terminal state for resume write-back: drop the throttle/ordering entry so the map doesn't
-        # retain a dead key for every finished item.
-        with _push_throttle_lock:
-            _last_push_at.pop((user.id, it.id), None)
-        db.commit()
-        # Immediate on the watched transition; skip a repeat scrobble if it was already watched
-        # (a later checkpoint of the same finished item would otherwise bump Plex's viewCount again).
-        if not was_watched:
-            _push_watch(background, db, user.id, it.id, rating_key, "watched")
-        return {"status": "watched", "position_seconds": 0}
 
     if position < _PROGRESS_MIN_S:
         if st is not None and st.status == "new":
@@ -372,7 +402,7 @@ def item_progress(
             st.position_seconds = 0
             st.progress_updated_at = now
         db.commit()
-        return {"position_seconds": 0}
+        return {"ok": True, "position_seconds": 0}
 
     if st is None:
         st = PlexState(user_id=user.id, item_id=it.id)
@@ -397,7 +427,7 @@ def item_progress(
             duration * 1000,
             intent=now,
         )
-    return {"position_seconds": position}
+    return {"ok": True, "position_seconds": position}
 
 
 class ItemStateIn(BaseModel):
@@ -418,7 +448,7 @@ def item_state(
     it = item_or_404(db, rating_key)
     status = body.status
     if status not in ("new", "watched", "hidden"):
-        raise HTTPException(status_code=400, detail="Invalid status")
+        raise refused(400, "invalid_status")
     st = (
         db.execute(
             select(PlexState).where(PlexState.user_id == user.id, PlexState.item_id == it.id)
@@ -443,7 +473,7 @@ def item_state(
             db.commit()
         if mirrored_on_plex:
             _push_watch(background, db, user.id, it.id, rating_key, "unwatched")
-        return {"status": "new"}
+        return {"ok": True, "status": "new"}
     if st is None:
         st = PlexState(user_id=user.id, item_id=it.id)
         db.add(st)
@@ -455,7 +485,7 @@ def item_state(
     db.commit()
     if status == "watched" and prev_status != "watched":
         _push_watch(background, db, user.id, it.id, rating_key, "watched")
-    return {"status": status}
+    return {"ok": True, "status": status}
 
 
 def _bulk_state(
@@ -497,7 +527,9 @@ def _bulk_state(
                 db.delete(st)
                 if prev != "new":
                     to_push.append((e.id, e.rating_key, "unwatched"))
-    db.commit()
+    # Flush, not commit: the handler commits, and it does so before the response — which is when
+    # the background push below runs, so the push always reads the committed marks.
+    db.flush()
     if pushable and to_push:
         # One coalesced background task for the whole batch (reuses a single session + Plex client),
         # not one task per episode — a 200-ep show mark is 1 task, not 200.
@@ -520,7 +552,7 @@ def show_state(
     """Mark a whole show watched/unwatched (all its episodes) for the current user + push to Plex."""
     sh = by_rating_key(db, PlexShow, rating_key)
     if sh is None:
-        raise HTTPException(status_code=404, detail="Unknown Plex show")
+        raise not_found("show")
     watched = body.watched
     eps = (
         db.execute(select(PlexItem).where(PlexItem.show_id == sh.id, PlexItem.kind == "episode"))
@@ -528,7 +560,8 @@ def show_state(
         .all()
     )
     changed = _bulk_state(background, db, user.id, eps, watched)
-    return {"changed": changed, "watched": watched}
+    db.commit()
+    return {"ok": True, "changed": changed, "watched": watched}
 
 
 @router.post("/season/{rating_key}/state")
@@ -542,7 +575,7 @@ def season_state(
     """Mark a whole season watched/unwatched (all its episodes) for the current user + push to Plex."""
     se = by_rating_key(db, PlexSeason, rating_key)
     if se is None:
-        raise HTTPException(status_code=404, detail="Unknown Plex season")
+        raise not_found("season")
     watched = body.watched
     eps = (
         db.execute(select(PlexItem).where(PlexItem.season_id == se.id, PlexItem.kind == "episode"))
@@ -550,7 +583,8 @@ def season_state(
         .all()
     )
     changed = _bulk_state(background, db, user.id, eps, watched)
-    return {"changed": changed, "watched": watched}
+    db.commit()
+    return {"ok": True, "changed": changed, "watched": watched}
 
 
 @router.post("/stream/{rating_key}/session")
@@ -575,21 +609,23 @@ def stream_session(
     # the client can switch audio without a restart — even for otherwise direct-playable files.
     if it.playable == "direct" and audio is None and not aoff and not multi:
         return {
+            "ok": True,
             "mode": "direct",
             "url": f"/api/plex/stream/{it.rating_key}/file",
             "start_s": 0.0,
         }
     if plex_paths.local_media_path(db, it.file_path) is None:
-        raise HTTPException(status_code=404, detail="Media file not found on disk")
-    s = plex_stream.start_session(db, it, start, audio, aoff, multi, transcode=transcode)
+        raise refused(404, "media_missing")
+    s = plex_stream.start_session(db, it, user.id, start, audio, aoff, multi, transcode=transcode)
     if s is None:
-        raise HTTPException(status_code=404, detail="Media file not found on disk")
+        raise refused(404, "media_missing")
     # Report the REAL media start (the keyframe ffmpeg landed on, which hls.js zero-bases to), not the
     # requested offset — the client's absolute clock and the subtitle cue-shift both key off this.
     # `transcode`/`hw`/`tonemap` let the player show an honest cold-start ("Preparing stream…") and
     # surface the active mode + encoder in the stats overlay (`tonemap` = the HW HDR→SDR path); both
     # segment streams are otherwise identical.
     return {
+        "ok": True,
         "mode": "hls",
         "start_s": s.media_start_s,
         # The session id is part of the path (not a query param) so the playlist's RELATIVE segment
@@ -614,7 +650,7 @@ def stream_file(
     it = item_or_404(db, rating_key)
     src = plex_paths.local_media_path(db, it.file_path)
     if src is None:
-        raise HTTPException(status_code=404, detail="Media file not found on disk")
+        raise refused(404, "media_missing")
     if download:
         # A clean, safe download name from the title + the real file extension.
         ext = src.suffix or (f".{it.container}" if it.container else "")
@@ -651,9 +687,9 @@ def stream_hls_file(
     references its segments/subtitles by relative name, all resolving back here.
 
     The session id in the path is what makes "back here" mean the same session. Sessions are keyed by
-    rating_key alone and a seek-restart or a second viewer of the same item replaces the registered
-    one, while the DIRECTORY is per (key, offset, tag) — so resolving by rating_key handed the old
-    viewer the new session's `seg_12.ts`, produced from a different offset under `-copyts`: wrong
+    (viewer, rating_key) and a seek-restart replaces the viewer's registered one, while the DIRECTORY
+    is per (key, viewer, offset, tag) — so resolving by the key alone handed the old player the new
+    session's `seg_12.ts`, produced from a different offset under `-copyts`: wrong
     bytes with a 200, which the player has no way to notice (deep-review round 5). A request for a
     session that is no longer the registered one is a 404, and the player reclaims at the playhead.
 
@@ -668,10 +704,10 @@ def stream_hls_file(
         or "\\" in filename
         or ".." in filename
     ):
-        raise HTTPException(status_code=404, detail="Not found")
-    s = plex_stream.current_session(str(rating_key))
+        raise not_found("file")
+    s = plex_stream.current_session(user.id, str(rating_key))
     if s is None or s.id != session_id:
-        raise HTTPException(status_code=404, detail="No active playback session")
+        raise refused(404, "session_gone")
     path = s.dir / filename
     # Only a name THIS session can actually produce is worth waiting for: its own playlists, and a
     # segment of one of its own renditions whose predecessor is already on disk (ffmpeg writes them
@@ -681,14 +717,14 @@ def stream_hls_file(
     # past the produced region — or a deliberate flood of hopeless names — from parking threadpool
     # workers and their DB connections (see `artifact_may_arrive`).
     if not plex_stream.artifact_may_arrive(s, filename):
-        raise HTTPException(status_code=404, detail="Not available yet")
+        raise refused(404, "not_ready")
     timeout = 30 if ext == ".m3u8" else 20
     # `proc` so a session whose ffmpeg has already exited answers at once instead of polling out the
     # whole timeout: this is a SYNC route on the ~40-slot threadpool, holding a pooled DB connection
     # with it, so every such wait is a worker (and a connection) parked for 20 s — an ordinary seek
     # past the produced region was enough to do it (round 5).
     if not plex_stream.wait_for(path, timeout, proc=s.proc):
-        raise HTTPException(status_code=404, detail="Not available yet")
+        raise refused(404, "not_ready")
     try:
         content = path.read_bytes()
     except OSError:
@@ -699,7 +735,7 @@ def stream_hls_file(
         # restarting at the playhead. Ordinary trigger: `loadSession` awaits the new session — which
         # kills and rmtrees the old one — before destroying the old hls instance, so the outgoing
         # instance's in-flight segment request races the rmtree on every seek-restart.
-        raise HTTPException(status_code=404, detail="No active playback session") from None
+        raise refused(404, "session_gone") from None
     return Response(
         content=content,
         media_type=_HLS_CT[ext],

backend/app/routes/plex/playlists.py

@@ -2,7 +2,7 @@
 
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import delete, func, select, update
 from sqlalchemy.orm import Session
@@ -19,15 +19,12 @@ from app.models import (
 )
 from app.plex.cards import leaf_card
 from app.plex.lookups import by_rating_key
-from app.routes._common import owned_or_404
+from app.routes._common import owned_or_404, not_found
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/plex", tags=["plex"])
 
 
-def _own_playlist_or_404(db: Session, pid: int, user: User) -> PlexPlaylist:
-    return owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
-
-
 def _playlist_card(pl: PlexPlaylist, count: int, thumb_rk: str | None) -> dict:
     return {
         "id": pl.id,
@@ -120,7 +117,7 @@ def create_playlist(
 ) -> dict:
     title = body.title.strip()
     if not title:
-        raise HTTPException(status_code=400, detail="title is required")
+        raise refused(400, "title_required")
     pl = PlexPlaylist(user_id=user.id, title=title)
     db.add(pl)
     db.flush()
@@ -140,7 +137,7 @@ def create_playlist(
 def playlist_detail(
     pid: int, user: User = Depends(current_user), db: Session = Depends(get_db)
 ) -> dict:
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     rows = db.execute(_playlist_item_query(pid)).all()
     items = [it for (_pi, it) in rows]
     states = {
@@ -183,10 +180,10 @@ def rename_playlist(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     title = body.title.strip()
     if not title:
-        raise HTTPException(status_code=400, detail="title is required")
+        raise refused(400, "title_required")
     pl.title = title
     db.commit()
     count = (
@@ -203,7 +200,7 @@ def rename_playlist(
 def delete_playlist(
     pid: int, user: User = Depends(current_user), db: Session = Depends(get_db)
 ) -> dict:
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     db.delete(pl)
     db.commit()
     return {"deleted": pid}
@@ -220,10 +217,10 @@ def playlist_add_item(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     it = by_rating_key(db, PlexItem, body.item_rating_key)
     if it is None:
-        raise HTTPException(status_code=404, detail="Unknown item")
+        raise not_found("item")
     exists = (
         db.execute(
             select(PlexPlaylistItem).where(
@@ -252,7 +249,7 @@ def playlist_remove_item(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     it = by_rating_key(db, PlexItem, item_rating_key)
     if it is not None:
         db.execute(
@@ -297,7 +294,7 @@ def playlist_add_bulk(
 ) -> dict:
     """Append many items at once (a whole season/show). Already-present items are skipped; the input
     order is preserved for the newly-added ones. Returns how many were added + the new total."""
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     items = _items_by_rks(db, body.item_rating_keys)
     existing = set(
         db.execute(
@@ -328,7 +325,7 @@ def playlist_add_bulk(
         )
         or 0
     )
-    return {"added": added, "item_count": total}
+    return {"ok": True, "added": added, "item_count": total}
 
 
 @router.post("/playlists/{pid}/items/remove-bulk")
@@ -340,7 +337,7 @@ def playlist_remove_bulk(
 ) -> dict:
     """Remove many items at once (a whole season/show, or a multi-select). Returns how many were
     removed + the new total."""
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     ids = [it.id for it in _items_by_rks(db, body.item_rating_keys)]
     removed = 0
     if ids:
@@ -359,7 +356,7 @@ def playlist_remove_bulk(
         )
         or 0
     )
-    return {"removed": removed, "item_count": total}
+    return {"ok": True, "removed": removed, "item_count": total}
 
 
 @router.put("/playlists/{pid}/order")
@@ -370,7 +367,7 @@ def reorder_playlist(
     db: Session = Depends(get_db),
 ) -> dict:
     """Set the playlist order from an explicit list of item rating_keys (0-based positions)."""
-    pl = _own_playlist_or_404(db, pid, user)
+    pl = owned_or_404(db, PlexPlaylist, pid, user, what="playlist")
     order = body.item_rating_keys
     id_by_rk = {
         it.rating_key: it.id

backend/app/routes/public.py

@@ -6,7 +6,7 @@ the app or any account data. Password-protected links exchange the password once
 a short-lived signed grant that the media URL carries (a `<video src>` can't send a header).
 """
 
-from fastapi import APIRouter, Depends, HTTPException, Request
+from fastapi import APIRouter, Depends, Request
 from fastapi.responses import FileResponse
 from pydantic import BaseModel
 from sqlalchemy import select
@@ -19,6 +19,8 @@ from app.downloads import storage
 from app.models import DownloadJob, DownloadLink, MediaAsset
 from app.ratelimit import RateLimiter, client_key
 from app.security import verify_password
+from app.refusal import refused
+from app.routes._common import not_found
 
 router = APIRouter(prefix="/api/public", tags=["public"])
 
@@ -37,7 +39,7 @@ _unlock_failures = RateLimiter(max_events=50, window_seconds=300)
 def _link_or_404(db: Session, token: str) -> DownloadLink:
     link = db.execute(select(DownloadLink).where(DownloadLink.token == token)).scalar_one_or_none()
     if link is None or linksmod.is_expired(link):
-        raise HTTPException(status_code=404, detail="This link is no longer available.")
+        raise refused(404, "link_gone")
     return link
 
 
@@ -45,12 +47,12 @@ def _ready_target(db: Session, link: DownloadLink) -> tuple[DownloadJob, MediaAs
     job = db.get(DownloadJob, link.job_id)
     asset = db.get(MediaAsset, job.asset_id) if job and job.asset_id else None
     if job is None or asset is None or asset.status != "ready" or not asset.rel_path:
-        raise HTTPException(status_code=404, detail="This video is no longer available.")
+        raise refused(404, "video_gone")
     # Verify the file is actually on disk here (not just flagged ready), so the watch page never
     # loads a player for a missing file — meta and file agree.
     path = storage.safe_abs_path(settings.download_root, asset.rel_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="This video is no longer available.")
+        raise refused(404, "video_gone")
     return job, asset
 
 
@@ -100,22 +102,24 @@ def watch_unlock(
     link = _link_or_404(db, token)
     viewer = f"{token}|{client_key(request)}"
     if _unlock_failures.exhausted(token) or not _unlock_limit.allow(viewer):
-        raise HTTPException(status_code=429, detail="Too many attempts. Try again later.")
+        raise refused(429, "too_many_attempts")
     if not link.password_hash:
         # Not a password link — nothing to unlock; just hand back the plain meta.
         job, asset = _ready_target(db, link)
         return {
+            "ok": True,
             "needs_password": False,
             **linksmod.public_meta(link, job, asset, _file_url(token), _poster_url(token, asset)),
         }
     if not verify_password(body.password, link.password_hash):
         _unlock_failures.allow(token)
-        raise HTTPException(status_code=403, detail="Wrong password.")
+        raise refused(403, "wrong_share_password")
     job, asset = _ready_target(db, link)
     link.view_count += 1
     db.commit()
     grant = linksmod.make_grant(token, link.password_version)
     return {
+        "ok": True,
         "needs_password": False,
         **linksmod.public_meta(
             link, job, asset, _file_url(token, grant), _poster_url(token, asset, grant)
@@ -129,11 +133,11 @@ def watch_file(token: str, g: str | None = None, db: Session = Depends(get_db)):
     `allow_download` link serves it as an attachment. Password links require a valid grant."""
     link = _link_or_404(db, token)
     if link.password_hash and not linksmod.check_grant(token, g, link.password_version):
-        raise HTTPException(status_code=403, detail="This link needs a password.")
+        raise refused(403, "share_password_required")
     asset = _ready_asset(db, link)
     path = storage.safe_abs_path(settings.download_root, asset.rel_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="This video is no longer available.")
+        raise refused(404, "video_gone")
 
     filename = storage.download_filename(asset.title or "video", asset.container, path)
     # The served Content-Type comes from the asset's ffprobe-verified media_kind + a container
@@ -163,11 +167,11 @@ def watch_poster(token: str, g: str | None = None, db: Session = Depends(get_db)
     and the link-preview image). Password links require a valid grant, like the file."""
     link = _link_or_404(db, token)
     if link.password_hash and not linksmod.check_grant(token, g, link.password_version):
-        raise HTTPException(status_code=403, detail="This link needs a password.")
+        raise refused(403, "share_password_required")
     job, asset = _ready_target(db, link)
     if not asset.poster_path:
-        raise HTTPException(status_code=404, detail="No poster.")
+        raise not_found("poster")
     path = storage.safe_abs_path(settings.download_root, asset.poster_path)
     if path is None:
-        raise HTTPException(status_code=404, detail="No poster.")
+        raise not_found("poster")
     return FileResponse(path, media_type="image/jpeg")

backend/app/routes/saved_views.py

@@ -1,4 +1,4 @@
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import func, select, update
 from sqlalchemy.exc import IntegrityError
@@ -8,6 +8,7 @@ from app.auth import require_human
 from app.db import get_db
 from app.models import SavedView, User
 from app.routes._common import owned_or_404
+from app.refusal import refused
 
 # Saved "smart views": per-user named snapshots of a module's filters (feed or plex, keyed by
 # `source`). Gated behind require_human so the shared demo account can't pollute a communal list
@@ -66,7 +67,7 @@ def create_view(
 ) -> dict:
     name = body.name.strip()
     if not name:
-        raise HTTPException(status_code=400, detail="name is required")
+        raise refused(400, "name_required")
     source = _norm_source(body.source)
     # Position is per (user, source), so each module's views number 0..N independently.
     maxpos = db.execute(
@@ -86,14 +87,10 @@ def create_view(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise HTTPException(status_code=409, detail=f"You already have a view named “{name}”.")
+        raise refused(409, "view_name_taken", name=name)
     return _serialize(view)
 
 
-def _own_view(db: Session, user: User, view_id: int) -> SavedView:
-    return owned_or_404(db, SavedView, view_id, user, what="view")
-
-
 class UpdateViewIn(BaseModel):
     # PATCH: presence decides what's touched (read via model_fields_set). filters, when sent,
     # must be a real object — an explicit null is rejected (a view can't have null filters).
@@ -109,16 +106,16 @@ def update_view(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    view = _own_view(db, user, view_id)
+    view = owned_or_404(db, SavedView, view_id, user, what="view")
     sent = body.model_fields_set
     if "name" in sent:
         name = (body.name or "").strip()
         if not name:
-            raise HTTPException(status_code=400, detail="name cannot be empty")
+            raise refused(400, "name_required")
         view.name = name[:80]
     if "filters" in sent:
         if body.filters is None:
-            raise HTTPException(status_code=400, detail="filters must be an object")
+            raise refused(400, "filters_not_object")
         view.filters = body.filters
     if "is_default" in sent:
         make_default = bool(body.is_default)
@@ -138,7 +135,7 @@ def update_view(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise HTTPException(status_code=409, detail=f"You already have a view named “{view.name}”.")
+        raise refused(409, "view_name_taken", name=view.name)
     return _serialize(view)
 
 
@@ -148,7 +145,7 @@ def delete_view(
     user: User = Depends(require_human),
     db: Session = Depends(get_db),
 ) -> dict:
-    view = _own_view(db, user, view_id)
+    view = owned_or_404(db, SavedView, view_id, user, what="view")
     db.delete(view)
     db.commit()
     return {"deleted": view_id}

backend/app/routes/scheduler.py

@@ -2,7 +2,7 @@
 per-job run activity (from the in-process scheduler), the work still queued (DB-derived),
 and the shared quota picture."""
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import and_, func, or_, select
 from sqlalchemy.orm import Session
@@ -25,6 +25,8 @@ from app.scheduler import (
 from app.sync.explore import followed_channel
 from app.sync.runner import estimate_deep_backfill
 from app.routes._common import not_found
+from app.refusal import refused
+from app.refusal import setting_refused
 
 router = APIRouter(prefix="/api/admin/scheduler", tags=["admin"])
 
@@ -46,10 +48,7 @@ def set_job_interval(
         raise not_found("job")
     minutes = body.interval_minutes
     if not (MIN_INTERVAL <= minutes <= MAX_INTERVAL):
-        raise HTTPException(
-            status_code=400,
-            detail=f"interval must be between {MIN_INTERVAL} and {MAX_INTERVAL} minutes",
-        )
+        raise refused(400, "invalid_interval", min=MIN_INTERVAL, max=MAX_INTERVAL)
     applied = apply_interval(db, job_id, minutes)
     audit.record(
         db,
@@ -61,7 +60,7 @@ def set_job_interval(
         after={"interval_minutes": applied},
     )
     db.commit()
-    return {"id": job_id, "interval_minutes": applied}
+    return {"ok": True, "id": job_id, "interval_minutes": applied}
 
 
 @router.post("/jobs/{job_id}/run")
@@ -77,14 +76,14 @@ def run_job_now(
     except KeyError:
         raise not_found("job")
     if result == "already_running":
-        raise HTTPException(status_code=409, detail="Job is already running")
-    return {"id": job_id, "started": True}
+        raise refused(409, "job_running")
+    return {"ok": True, "id": job_id, "started": True}
 
 
 @router.post("/run-all")
 def run_all_now(user: User = Depends(admin_user)) -> dict:
     """Trigger every job that isn't already running. Returns the ids actually started."""
-    return {"started": trigger_all(actor_id=user.id)}
+    return {"ok": True, "started": trigger_all(actor_id=user.id)}
 
 
 class MaintenanceSettingsIn(BaseModel):
@@ -102,8 +101,8 @@ def set_maintenance_settings(
     # set_value validates against the spec's min/max (one source of bounds), mirroring the config PATCH.
     try:
         sysconfig.set_value(db, "maintenance_revalidate_batch", body.revalidate_batch)
-    except (TypeError, ValueError) as exc:
-        raise HTTPException(status_code=400, detail=str(exc) or "Invalid value")
+    except sysconfig.InvalidSetting as exc:
+        raise setting_refused(exc) from None
     new = sysconfig.get_int(db, "maintenance_revalidate_batch")
     audit.record(
         db,
@@ -113,7 +112,7 @@ def set_maintenance_settings(
         after={"revalidate_batch": new},
     )
     db.commit()
-    return {"revalidate_batch": new}
+    return {"ok": True, "revalidate_batch": new}
 
 
 @router.get("")

backend/app/routes/search.py

@@ -16,7 +16,7 @@ dropped from the search response up front)."""
 from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import and_, delete, func, or_, select, update
 from sqlalchemy.dialects.postgresql import insert as pg_insert
@@ -38,11 +38,14 @@ from app.models import (
     VideoState,
 )
 from app.feedquery import feed_columns, serialize
+from app.utils import like_escape
 from app.sync.subscriptions import apply_channel_details
 from app.sync.videos import insert_stubs, apply_video_details, parse_dt
 from app.youtube import search_scrape
 from app.youtube.client import YouTubeClient, YouTubeError
 from app.youtube.shorts import make_client, probe_is_short
+from app.refusal import refused
+from app.routes._common import youtube_refusal
 
 log = logs.get_logger(__name__)
 router = APIRouter(prefix="/api/search", tags=["search"])
@@ -224,6 +227,25 @@ def _new_first(db: Session, user: User, ids: list[str]) -> list[str]:
     return [i for i in ids if i not in have] + [i for i in ids if i in have]
 
 
+def _fold_term(db: Session, video_ids: list[str], term: str) -> None:
+    """Append `term` to each video's space-joined `search_terms`, unless it is already one of them.
+
+    "Already one of them" is a whole-term match, as a literal: a substring test skipped `cat` on a
+    video already found for `category`, and an unescaped one read the `_` in `my_channel` as a
+    wildcard — either way the term was never folded in, and local search lost that relevance."""
+    padded = func.concat(" ", func.coalesce(Video.search_terms, ""), " ")
+    db.execute(
+        update(Video)
+        .where(Video.id.in_(video_ids))
+        .where(padded.notilike(f"% {like_escape(term)} %"))
+        .values(
+            search_terms=func.trim(
+                func.coalesce(Video.search_terms, "").op("||")(" ").op("||")(term)
+            )
+        )
+    )
+
+
 @router.get("/youtube")
 def search_youtube(
     q: str | None = None,
@@ -238,7 +260,7 @@ def search_youtube(
     page, so it returns a single page (≤50) regardless. `cursor` lets the caller fetch further."""
     term = (q or "").strip()
     if not term:
-        raise HTTPException(status_code=400, detail="A search term is required.")
+        raise refused(400, "search_term_required")
     limit = max(1, min(limit, 100))
 
     # Source: "scrape" (InnerTube, no API quota) or "api" (search.list, 100 units/page).
@@ -255,20 +277,14 @@ def search_youtube(
             "a live search was refused: the per-user daily cap is spent",
             extra=logs.event("search.refused", reason="daily_cap", limit=daily_limit),
         )
-        raise HTTPException(
-            status_code=429,
-            detail=f"You've reached today's YouTube search limit ({daily_limit}). Try again tomorrow.",
-        )
+        raise refused(429, "search_daily_limit", limit=daily_limit)
     # The 100-unit budget pre-check only applies to the API source.
     if source == "api" and not quota.can_spend(db, SEARCH_COST):
         log.info(
             "a live search was refused: the shared YouTube budget is spent",
             extra=logs.event("search.refused", reason="shared_quota", cost=SEARCH_COST),
         )
-        raise HTTPException(
-            status_code=429,
-            detail="The shared YouTube quota for today is used up. Try again tomorrow.",
-        )
+        raise refused(429, "quota_spent")
 
     # Channels this user has blocked are dropped before ingestion — never shown, never stored.
     blocked = set(
@@ -293,9 +309,14 @@ def search_youtube(
                 # dropout (auto-retry + "connection lost" banner — lib/api/core RETRIABLE_GATEWAY),
                 # which hides the real message and burns a second quota-costed search. Upstream failure
                 # on a JSON endpoint = 422 + message; reserve 5xx for the raw byte-proxies. (B-core-1)
-                raise HTTPException(
-                    status_code=422, detail=f"YouTube search failed: {exc}"
-                ) from exc
+                # A Data API failure is logged where it happened; the scraper's is not, and its text
+                # no longer rides the answer — so it is said here.
+                if isinstance(exc, search_scrape.ScrapeError):
+                    log.warning(
+                        "the YouTube search scrape failed",
+                        extra=logs.event("search.scrape_failed", error=str(exc)),
+                    )
+                raise youtube_refusal(exc) from exc
 
             # Drop currently-live/upcoming, channel-less, and blocked-channel results.
             candidates = [
@@ -337,9 +358,7 @@ def search_youtube(
                     )
                 if collected:
                     break  # keep what earlier pages already gathered
-                raise HTTPException(
-                    status_code=422, detail=f"YouTube search failed: {exc}"
-                ) from exc
+                raise youtube_refusal(exc) from exc
             next_cursor = page["next_page_token"]
             # The API source pages cost 100 units each — never auto-page; one page per request.
             if source == "api" or len(collected) >= limit or not next_cursor:
@@ -364,16 +383,7 @@ def search_youtube(
             .values([{"user_id": user.id, "video_id": vid} for vid in ordered])
             .on_conflict_do_nothing(index_elements=["user_id", "video_id"])
         )
-        db.execute(
-            update(Video)
-            .where(Video.id.in_(ordered))
-            .where(func.coalesce(Video.search_terms, "").notilike(f"%{term}%"))
-            .values(
-                search_terms=func.trim(
-                    func.coalesce(Video.search_terms, "").op("||")(" ").op("||")(term)
-                )
-            )
-        )
+        _fold_term(db, ordered, term)
         db.commit()
 
     ordered = _new_first(db, user, ordered)
@@ -401,7 +411,7 @@ def clear_search(
     find. Kept videos and organically-owned ones are left untouched."""
     ids = body.video_ids
     if not ids:
-        return {"removed": 0}
+        return {"ok": True, "removed": 0}
     db.execute(
         delete(SearchFind).where(SearchFind.user_id == user.id, SearchFind.video_id.in_(ids))
     )
@@ -421,4 +431,4 @@ def clear_search(
         )
     ).rowcount
     db.commit()
-    return {"removed": removed}
+    return {"ok": True, "removed": removed}

backend/app/routes/setup.py

@@ -8,7 +8,7 @@ X-Setup-Token header).
 
 from typing import Any
 
-from fastapi import APIRouter, Depends, Header, HTTPException
+from fastapi import APIRouter, Depends, Header
 from pydantic import BaseModel
 from sqlalchemy import select
 from sqlalchemy.orm import Session
@@ -21,6 +21,8 @@ from app.auth import PASSWORD_MIN_LEN
 from app.db import get_db
 from app.models import User
 from app.security import hash_password
+from app.refusal import refused
+from app.refusal import setting_refused
 
 router = APIRouter(prefix="/api/setup", tags=["setup"])
 
@@ -31,9 +33,9 @@ def require_setup(
 ) -> Session:
     """Gate for setup steps. Returns the db session for the handler to reuse."""
     if state.is_configured(db):
-        raise HTTPException(status_code=409, detail="This instance is already set up.")
+        raise refused(409, "already_set_up")
     if not state.check_setup_token(db, x_setup_token):
-        raise HTTPException(status_code=403, detail="Invalid or missing setup token.")
+        raise refused(403, "setup_token")
     return db
 
 
@@ -66,11 +68,9 @@ def setup_admin(body: SetupAdminIn, db: Session = Depends(require_setup)) -> dic
     email = body.email.strip().lower()
     password = body.password
     if "@" not in email:
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     if len(password) < PASSWORD_MIN_LEN:
-        raise HTTPException(
-            status_code=400, detail=f"Password must be at least {PASSWORD_MIN_LEN} characters."
-        )
+        raise refused(400, "weak_password", min=PASSWORD_MIN_LEN)
     # Resolve canonically, not by the literal string (DX-17). The wizard can be re-run, and E9.5's
     # whole point is that two spellings of one Gmail mailbox are one person — matching literally here
     # would let a second run under the other spelling create the DUPLICATE admin row the epic exists
@@ -97,16 +97,16 @@ def setup_config(settings_map: dict[str, Any], db: Session = Depends(require_set
     saved: list[str] = []
     for key, value in settings_map.items():
         if sysconfig.spec(key) is None:
-            raise HTTPException(status_code=400, detail=f"Unknown setting: {key}")
+            raise refused(400, "unknown_setting", key=key)
         if value is None or value == "":
             continue
         try:
             sysconfig.set_value(db, key, value)
-        except (ValueError, RuntimeError) as exc:
-            raise HTTPException(status_code=400, detail=str(exc))
+        except sysconfig.InvalidSetting as exc:
+            raise setting_refused(exc) from None
         saved.append(key)
     db.commit()  # sysconfig.set_value only flushes now — persist the wizard's config in one commit
-    return {"saved": saved}
+    return {"ok": True, "saved": saved}
 
 
 class SetupTestEmailIn(BaseModel):
@@ -121,9 +121,9 @@ def setup_test_email(body: SetupTestEmailIn, db: Session = Depends(require_setup
     """Send a test email to confirm the SMTP settings the wizard just saved."""
     to = body.to.strip()
     if "@" not in to:
-        raise HTTPException(status_code=400, detail="Enter a valid email address.")
+        raise refused(400, "invalid_email")
     if not email_mod.send_test(to, mailtext.normalize(body.lang)):
-        raise HTTPException(status_code=400, detail="Couldn't send — check the SMTP settings.")
+        raise refused(400, "smtp_failed")
     return {"ok": True}
 
 
@@ -133,6 +133,6 @@ def setup_finish(db: Session = Depends(require_setup)) -> dict:
     invalidates the setup token and disables the wizard)."""
     has_admin = db.execute(select(User).where(User.role == "admin")).first() is not None
     if not has_admin:
-        raise HTTPException(status_code=400, detail="Create the admin account first.")
+        raise refused(400, "admin_first")
     state.mark_configured(db)
     return {"ok": True}

backend/app/routes/sync.py

@@ -7,10 +7,13 @@ from app.audit import AuditAction
 from app.auth import admin_user, current_user, has_read_scope, require_human
 from app.db import get_db
 from app.models import Channel, Subscription, User, Video
+from app.routes._common import youtube_refusal
 from app.ratelimit import RateLimiter
 from app.sync.runner import estimate_deep_backfill
 from app.sync.subscriptions import import_subscriptions
 from app.scheduler import running_job_ids
+from app.youtube.client import YouTubeError
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/sync", tags=["sync"])
 
@@ -26,17 +29,20 @@ _sync_limiter = RateLimiter(max_events=3, window_seconds=600)
 def sync_subscriptions(user: User = Depends(require_human), db: Session = Depends(get_db)) -> dict:
     if not has_read_scope(user):
         # No YouTube read grant yet — the onboarding wizard hasn't been completed.
-        raise HTTPException(
-            status_code=403,
-            detail="Connect your YouTube account (read access) to import subscriptions.",
-        )
+        raise refused(403, "youtube_read_scope")
     if not _sync_limiter.allow(str(user.id)):
         raise HTTPException(status_code=429, detail={"code": "sync_cooldown"})
-    with quota.measured(db, user.id, quota.QuotaAction.SUBSCRIPTIONS_PULL) as m:
-        result = import_subscriptions(db, user)
+    try:
+        with quota.measured(db, user.id, quota.QuotaAction.SUBSCRIPTIONS_PULL) as m:
+            result = import_subscriptions(db, user)
+    except YouTubeError as exc:
+        # The onboarding wizard's first call: an unguarded failure here was a raw 500 and the
+        # blocking "Server error" dialog, with nothing the user could act on (E9 F1).
+        db.rollback()
+        raise youtube_refusal(exc)
     result["quota_used_estimate"] = m.used
     result["quota_remaining_today"] = m.remaining
-    return result
+    return {"ok": True, **result}
 
 
 @router.get("/status")
@@ -137,7 +143,7 @@ def deep_all(
         update(Subscription).where(Subscription.user_id == user.id).values(deep_requested=on)
     )
     db.commit()
-    return {"updated": result.rowcount, "deep_requested": on}
+    return {"ok": True, "updated": result.rowcount, "deep_requested": on}
 
 
 @router.post("/pause")
@@ -145,7 +151,7 @@ def pause_sync(admin: User = Depends(admin_user), db: Session = Depends(get_db))
     state.set_sync_paused(db, True)
     audit.record(db, admin.id, AuditAction.SYNC_PAUSE, summary="Background sync paused")
     db.commit()
-    return {"paused": True}
+    return {"ok": True, "paused": True}
 
 
 @router.post("/resume")
@@ -153,4 +159,4 @@ def resume_sync(admin: User = Depends(admin_user), db: Session = Depends(get_db)
     state.set_sync_paused(db, False)
     audit.record(db, admin.id, AuditAction.SYNC_RESUME, summary="Background sync resumed")
     db.commit()
-    return {"paused": False}
+    return {"ok": True, "paused": False}

backend/app/routes/tags.py

@@ -1,4 +1,4 @@
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 from sqlalchemy import func, or_, select
 from sqlalchemy.exc import IntegrityError
@@ -9,6 +9,7 @@ from app.db import get_db
 from app.models import ChannelTag, Tag, User
 from app.routes._common import owned_or_404
 from app.sync.tagsuggest import compute_tag_suggestions
+from app.refusal import refused
 
 router = APIRouter(prefix="/api/tags", tags=["tags"])
 
@@ -60,7 +61,7 @@ def create_tag(
 ) -> dict:
     name = body.name.strip()
     if not name:
-        raise HTTPException(status_code=400, detail="name is required")
+        raise refused(400, "name_required")
     # An unknown category silently falls back to "other" (unchanged behaviour) rather than 422.
     category = body.category if body.category in ("language", "topic", "other") else "other"
     tag = Tag(
@@ -74,13 +75,14 @@ def create_tag(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise HTTPException(status_code=409, detail=f"You already have a tag named “{name}”.")
-    return {"id": tag.id, "name": tag.name, "color": tag.color, "category": tag.category}
-
-
-def _own_tag(db: Session, user: User, tag_id: int) -> Tag:
-    # System tags (user_id NULL) are not user-editable → owned_or_404 404s them too.
-    return owned_or_404(db, Tag, tag_id, user, what="tag")
+        raise refused(409, "tag_name_taken", name=name)
+    return {
+        "ok": True,
+        "id": tag.id,
+        "name": tag.name,
+        "color": tag.color,
+        "category": tag.category,
+    }
 
 
 class TagUpdateIn(BaseModel):
@@ -97,12 +99,13 @@ def update_tag(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    tag = _own_tag(db, user, tag_id)
+    # System tags (user_id NULL) are not user-editable: owned_or_404 404s them too.
+    tag = owned_or_404(db, Tag, tag_id, user, what="tag")
     sent = body.model_fields_set
     if "name" in sent:
         name = (body.name or "").strip()
         if not name:
-            raise HTTPException(status_code=400, detail="name cannot be empty")
+            raise refused(400, "name_required")
         tag.name = name
     if "color" in sent:
         tag.color = body.color
@@ -110,8 +113,14 @@ def update_tag(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise HTTPException(status_code=409, detail=f"You already have a tag named “{tag.name}”.")
-    return {"id": tag.id, "name": tag.name, "color": tag.color, "category": tag.category}
+        raise refused(409, "tag_name_taken", name=tag.name)
+    return {
+        "ok": True,
+        "id": tag.id,
+        "name": tag.name,
+        "color": tag.color,
+        "category": tag.category,
+    }
 
 
 @router.delete("/{tag_id}")
@@ -120,7 +129,8 @@ def delete_tag(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    tag = _own_tag(db, user, tag_id)
+    # System tags (user_id NULL) are not user-editable: owned_or_404 404s them too.
+    tag = owned_or_404(db, Tag, tag_id, user, what="tag")
     db.delete(tag)  # ChannelTag rows cascade on tag delete.
     db.commit()
     return {"deleted": tag_id}

backend/app/scheduler.py

@@ -9,7 +9,7 @@ from typing import Callable
 from apscheduler.schedulers.background import BackgroundScheduler
 from sqlalchemy import select
 
-from app import audit, logs, logsink, progress, quota
+from app import audit, debugsession, logs, logsink, progress, quota
 from app.audit import AuditAction
 from app.config import settings
 from app.db import SessionLocal
@@ -208,7 +208,7 @@ def _job(name: str, fn) -> None:
         _audit_run(db, actor_id, name, "ok", summary, result)
     except Exception as exc:
         db.rollback()
-        log.exception("job %s failed", name)
+        log.exception("job %s failed", name, extra=logs.event("scheduler.job.failed", job=name))
         err = str(exc) or exc.__class__.__name__
         _record(name, status="error", last_finished=_now_iso(), last_error=err, progress=None)
         if actor_id is not None:
@@ -386,9 +386,13 @@ def _log_gc_job() -> None:
     def work(db):
         from app import sysconfig
 
-        reaped = logsink.gc(db, sysconfig.get_int(db, "log_retention_days"))
+        days = sysconfig.get_int(db, "log_retention_days")
+        reaped = logsink.gc(db, days)
+        # Debug sessions (E16) go with the rows they bundle; an open one past its cap is closed.
+        closed = debugsession.sweep(db)
+        sessions = debugsession.gc(db, days)
         db.commit()
-        return {"reaped": reaped}
+        return {"reaped": reaped, "sessions_closed": closed, "sessions_reaped": sessions}
 
     _job("log_gc", work)
 

backend/app/sync/playlists.py

@@ -670,11 +670,19 @@ def sync_all_playlists(db: Session) -> dict:
         try:
             with quota.attribute(user.id, quota.QuotaAction.PLAYLISTS_PULL):
                 total += sync_user_playlists(db, user).get("synced", 0)
-        except YouTubeError:
+        except YouTubeError as exc:
             db.rollback()
-            log.warning("Playlist sync failed for user %s", user.id)
+            log.warning(
+                "Playlist sync failed for user %s",
+                user.id,
+                extra=logs.event("sync.playlists.failed", user_id=user.id, reason=exc.reason),
+            )
         except Exception:
             db.rollback()
-            log.exception("Playlist sync crashed for user %s", user.id)
+            log.exception(
+                "Playlist sync crashed for user %s",
+                user.id,
+                extra=logs.event("sync.playlists.crashed", user_id=user.id),
+            )
         progress.report(i, len(users), "playlist_sync")
     return {"users": len(users), "playlists_synced": total}

backend/app/sync/runner.py

@@ -9,8 +9,9 @@ import logging
 import threading
 from collections import Counter
 from concurrent.futures import ThreadPoolExecutor, as_completed
+from datetime import datetime, timedelta, timezone
 
-from sqlalchemy import select
+from sqlalchemy import func, or_, select, update
 from sqlalchemy.orm import Session
 
 from app import logs, progress, quota, sysconfig
@@ -25,11 +26,13 @@ from app.sync.videos import (
     backfill_channel_deep,
     backfill_channel_recent,
     enrich_pending,
+    insert_stubs,
     reconcile_full_history,
     refresh_live,
     run_shorts_classification,
+    stub_from_playlist_item,
 )
-from app.youtube.client import YouTubeClient
+from app.youtube.client import YouTubeClient, YouTubeError, is_quota_refusal
 from app.youtube.rss import RssError, fetch_channel_feed
 
 # RSS feeds are free and network-bound, so fetch many at once; DB writes stay single-threaded.
@@ -85,6 +88,9 @@ def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> dict[str
     # of 2026-09-16 into 11k warnings in four hours; each channel's own line is DEBUG now.
     reasons: Counter[str] = Counter()
     examples: list[str] = []
+    # Channels whose FEED would not answer (not those whose rows failed to apply: the API would
+    # hand the same rows to the same broken write) — the feed fallback's candidates.
+    unread: list[str] = []
 
     def fail(reason: str, detail: str, *, unexpected: str | None = None) -> None:
         """Count a channel that did not get polled. `unexpected` is the message for a failure that
@@ -120,6 +126,7 @@ def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> dict[str
             except RssError as exc:
                 log.debug("RSS poll skipped for channel %s: %s", channel.id, exc)
                 fail(exc.reason, f"{channel.id}: {exc}")
+                unread.append(channel.id)
             # silent-ok: `fail(unexpected=…)` is the report — it logs at ERROR with the
             # traceback, once per reason per poll, which is the flood control this loop needs.
             except Exception as exc:  # noqa: BLE001 — one channel must not stop the poll
@@ -143,17 +150,24 @@ def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> dict[str
             # One place that advances the counter, whatever happened above.
             done += 1
             progress.report(done, total, "rss_poll")
+    fallback = run_feed_fallback(db, unread)
     if failed:
+        # The fallback's count rides on this line because this is the one the stored log keeps (an
+        # INFO line outside a request never reaches `log_events`): the console should show whether
+        # the uploads came in another way.
         log.warning(
-            "RSS poll: %d/%d channels could not be polled",
+            "RSS poll: %d/%d channels could not be polled; %d read through the API instead",
             failed,
             total,
+            fallback["read"],
             extra=logs.event(
                 "sync.rss.failed",
                 failed=failed,
                 total=total,
                 reasons=dict(reasons),
                 examples=examples,
+                fallback_read=fallback["read"],
+                fallback_new=fallback["new"],
             ),
         )
     if total and failed == total:
@@ -164,8 +178,115 @@ def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> dict[str
         # subscriptions "all channels failed" is also what ONE dead feed id looks like, and a red
         # card the user can't act on is its own kind of dishonest. `channel: HTTP 404` says
         # "fix this subscription"; `Connection refused` says "the egress is down".
-        raise RuntimeError(f"RSS poll failed for all {total} channels — first: {first_error}")
-    return {"new": new, "failed": failed}
+        # The fallback's count rides along: a red card during an RSS outage should still say
+        # whether the uploads are arriving another way.
+        raise RuntimeError(
+            f"RSS poll failed for all {total} channels — first: {first_error}"
+            f" (read through the API instead: {fallback['read']})"
+        )
+    return {"new": new + fallback["new"], "failed": failed, "fallback": fallback["read"]}
+
+
+def run_feed_fallback(db: Session, channel_ids: list[str]) -> dict[str, int]:
+    """Read the newest uploads through the Data API for the channels among `channel_ids` whose feed
+    has not answered for `rss_fallback_hours` — and that were not read this way within as long.
+
+    YouTube's RSS goes dark per channel for hours at a time (2026-09-18/19: 393 of 396 feeds answered
+    404 for four hours, and a retry of the same channel gets the same 404), and nothing else reads a
+    followed channel's new uploads: recent backfill runs once per channel, ever. One page of the
+    uploads playlist is 1 unit, so a whole day of total outage costs 12 units per channel at the
+    default 2 hours; it yields to the backfill reserve like every other background read. The clock is
+    `last_rss_at` or `feed_fallback_at`, whichever is later, so a channel is read at most once per
+    window whether its feed came back in between or not. A read the API REFUSED stamps the clock
+    too: a terminated channel's uploads playlist answers 404 for good, and without the stamp it
+    would be charged again on every 20-minute poll instead of once per window. A failure that is not
+    about the channel (no connection, no token, the quota spent) stamps nothing and ends the round."""
+    hours = sysconfig.get_int(db, "rss_fallback_hours")
+    if hours <= 0 or not channel_ids:
+        return {"read": 0, "new": 0, "failed": 0}
+    now = datetime.now(timezone.utc)
+    last_read = func.greatest(Channel.last_rss_at, Channel.feed_fallback_at)
+    due = (
+        db.execute(
+            select(Channel)
+            .where(
+                Channel.id.in_(channel_ids),
+                Channel.uploads_playlist_id.is_not(None),
+                or_(last_read.is_(None), last_read < now - timedelta(hours=hours)),
+            )
+            .order_by(Channel.id)
+        )
+        .scalars()
+        .all()
+    )
+    user = get_service_user(db) if due else None
+    if user is None:
+        return {"read": 0, "new": 0, "failed": 0}
+    read = new = failed = 0
+    with (
+        quota.attribute(None, quota.QuotaAction.VIDEOS_FEED_FALLBACK),
+        YouTubeClient(db, user) as yt,
+    ):
+        for channel in due:
+            if quota.backfill_reserve_reached():
+                break
+            try:
+                data = yt.get_playlist_items(channel.uploads_playlist_id, None)
+            # silent-ok: counted, and the one summary line below names the count — the client
+            # already logged the call's own failure (`youtube.api.error`).
+            except YouTubeError as exc:
+                failed += 1
+                # Not an answer about THIS channel — no connection, no token, no quota: every
+                # further channel would fail the same way, and none of them has used its window.
+                if exc.path != "playlistItems" or is_quota_refusal(exc):
+                    break
+                _stamp_fallback_attempt(db, channel.id)
+                continue
+            rows = [
+                s
+                for s in (stub_from_playlist_item(it, channel.id) for it in data.get("items", []))
+                if s is not None
+            ]
+            try:
+                new += insert_stubs(db, rows)
+                channel.feed_fallback_at = datetime.now(timezone.utc)
+                db.add(channel)
+                db.commit()
+            except Exception:  # noqa: BLE001 — one channel must not stop the rest
+                db.rollback()
+                log.exception(
+                    "Feed fallback could not store channel %s",
+                    channel.id,
+                    extra=logs.event("sync.rss.fallback_failed"),
+                )
+                failed += 1
+                _stamp_fallback_attempt(db, channel.id)
+                continue
+            read += 1
+    log.info(
+        "Feed fallback: read %d of %d channels through the API, %d new videos",
+        read,
+        len(due),
+        new,
+        extra=logs.event("sync.rss.fallback", read=read, due=len(due), new=new, failed=failed),
+    )
+    return {"read": read, "new": new, "failed": failed}
+
+
+def _stamp_fallback_attempt(db: Session, channel_id: str) -> None:
+    """Start a channel's fallback window after a read that did not land, so it waits the window out
+    like a read that did. Its own commit: the failure already rolled the channel's work back."""
+    try:
+        db.execute(
+            update(Channel)
+            .where(Channel.id == channel_id)
+            .values(feed_fallback_at=datetime.now(timezone.utc))
+        )
+        db.commit()
+    # silent-ok: the failure that brought us here was already logged and counted; an unstamped
+    # channel is only read again at the next poll.
+    except Exception:  # noqa: BLE001
+        db.rollback()
 
 
 def run_enrich(db: Session, max_batches: int = 200, floor: int = 200) -> int:

backend/app/sysconfig.py

@@ -91,6 +91,7 @@ SPECS: tuple[ConfigSpec, ...] = (
     ConfigSpec(
         "backfill_recent_max_days", "int", "backfill", "backfill_recent_max_days", min=1, max=36_500
     ),
+    ConfigSpec("rss_fallback_hours", "int", "backfill", "rss_fallback_hours", min=0, max=168),
     # --- Shorts probe ---
     ConfigSpec(
         "shorts_probe_max_seconds", "int", "shorts", "shorts_probe_max_seconds", min=1, max=3_600
@@ -175,6 +176,7 @@ SPECS: tuple[ConfigSpec, ...] = (
     ConfigSpec("plex_overlay_map", "str", "plex", "plex_overlay_map"),
     # (plex_sync_interval_min is tuned from the Scheduler dashboard, not here — it's a scheduler job.)
     ConfigSpec("plex_max_transcodes", "int", "plex", "plex_max_transcodes", min=0, max=16),
+    ConfigSpec("plex_max_sessions", "int", "plex", "plex_max_sessions", min=1, max=64),
     # Transcode re-encode tuning (E6 S1). The libx264 knobs apply only to the software fallback.
     # crf 0–51 (x264 range); max_height 0 = source.
     ConfigSpec("plex_transcode_hw", "choice", "plex", "plex_transcode_hw"),
@@ -190,6 +192,10 @@ SPECS: tuple[ConfigSpec, ...] = (
     # --- TMDB enrichment (E5 S2; optional) — the API key is the only secret ---
     ConfigSpec("tmdb_api_key", "str", "tmdb", "tmdb_api_key", secret=True),
     ConfigSpec("tmdb_language", "str", "tmdb", "tmdb_language"),
+    # --- Bug reports (E16): the Gitea issue tracker a debug session's issue goes to ---
+    ConfigSpec("issues_gitea_url", "str", "issues", "issues_gitea_url"),
+    ConfigSpec("issues_gitea_repo", "str", "issues", "issues_gitea_repo"),
+    ConfigSpec("issues_gitea_token", "str", "issues", "issues_gitea_token", secret=True),
     # (tmdb_enrich_interval_min is a scheduler job, tuned from the Scheduler dashboard; tmdb_enrich_batch
     # is a config.py default — both stay out of SPECS, like plex_sync_interval_min.)
 )
@@ -210,11 +216,23 @@ def _default(s: ConfigSpec):
     return getattr(settings, s.default_attr)
 
 
+class InvalidSetting(ValueError):
+    """A value `set_value` refuses, as a reason the UI translates (`errors.refused.setting_<reason>`)
+    plus what the sentence needs — the English message is for logs only. A ValueError still, so a
+    caller that only needs "refused or not" keeps working."""
+
+    def __init__(self, key: str, reason: str, **params: object):
+        super().__init__(f"{key}: {reason} {params}")
+        self.key = key
+        self.reason = reason
+        self.params = params
+
+
 def _choice(s: ConfigSpec, raw: object) -> str:
-    """The canonical spelling of `raw` among the key's choices (any letter case), or ValueError."""
+    """The canonical spelling of `raw` among the key's choices (any letter case), or InvalidSetting."""
     option = canonical_choice(s.choices, raw)
     if option is None:
-        raise ValueError(f"{s.key} must be one of: {', '.join(s.choices)}")
+        raise InvalidSetting(s.key, "not_a_choice", choices=", ".join(s.choices))
     return option
 
 
@@ -304,11 +322,14 @@ def set_value(db: Session, key: str, value) -> None:
     (B-core-10). The staged value is visible to a same-session `get()` before the commit."""
     s = _BY_KEY[key]
     if s.type == "int":
-        v = int(value)
+        try:
+            v = int(value)
+        except (TypeError, ValueError):
+            raise InvalidSetting(key, "not_a_number") from None
         if s.min is not None and v < s.min:
-            raise ValueError(f"{key} must be >= {s.min}")
+            raise InvalidSetting(key, "too_low", min=s.min)
         if s.max is not None and v > s.max:
-            raise ValueError(f"{key} must be <= {s.max}")
+            raise InvalidSetting(key, "too_high", max=s.max)
         raw = str(v)
     elif s.type == "bool":
         raw = "true" if value else "false"
@@ -320,7 +341,7 @@ def set_value(db: Session, key: str, value) -> None:
     stored, encrypted = raw, False
     if s.secret:
         if not secrets_manageable():
-            raise RuntimeError("TOKEN_ENCRYPTION_KEY is not configured")
+            raise InvalidSetting(key, "no_encryption_key")
         stored, encrypted = security.encrypt(raw) or "", True
 
     row = db.get(SystemConfig, key)

backend/app/utils.py

@@ -73,6 +73,14 @@ def to_tsquery_str(q: str) -> str | None:
     return " & ".join(tokens)
 
 
+def like_escape(s: str) -> str:
+    """`s` as a LITERAL inside a LIKE/ILIKE pattern: `%` and `_` are wildcards there, and `\\` is
+    Postgres's default escape character, so all three are escaped. Every pattern built from text a
+    person typed goes through this — unescaped, a search for `100%` or `my_channel` matches rows it
+    should not."""
+    return s.replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_")
+
+
 def normalize_description(text: str | None) -> str | None:
     """Strip whitespace-only lines from a CHANNEL description before storing. YouTube channel
     descriptions pad their contact/link blocks with runs of blank lines; keeping them wastes storage,

backend/app/youtube/client.py

@@ -6,8 +6,10 @@ so they don't depend on a specific user's token; subscriptions.list?mine=true al
 uses OAuth.
 """
 
+import logging
 from collections.abc import Iterator
 from datetime import datetime, timedelta, timezone
+from typing import Literal
 
 import httpx
 
@@ -25,11 +27,15 @@ class YouTubeError(Exception):
 
     `reason` is the API's own error reason code (`quotaExceeded`, `subscriptionDuplicate`,
     `videoNotFound`, …) when the body carried one. Branch on THAT, never on the message: the
-    message is prose, it changes under us, and it is deliberately the poorer of the two here."""
+    message is prose, it changes under us, and it is deliberately the poorer of the two here.
 
-    def __init__(self, message: str, *, reason: str = ""):
+    `path` is the API endpoint that ANSWERED with the failure (`playlistItems`); empty when no
+    endpoint did — the request never got through (`transport`) or the token step refused first."""
+
+    def __init__(self, message: str, *, reason: str = "", path: str = ""):
         super().__init__(message)
         self.reason = reason
+        self.path = path
 
 
 def _error_reason(resp: httpx.Response) -> str:
@@ -50,7 +56,9 @@ def _error_reason(resp: httpx.Response) -> str:
     return reasons or "<none>"
 
 
-def _upstream_failure(method: str, path: str, resp: httpx.Response) -> YouTubeError:
+def _upstream_failure(
+    method: str, path: str, resp: httpx.Response, expected: frozenset[str] = frozenset()
+) -> YouTubeError:
     """Report one upstream failure and build the error to raise. Every YouTube response that is
     not a success goes through here — the Data API's reads, writes and deletes and the OAuth
     token refresh — so what may appear in a log line cannot drift apart between them, and the
@@ -59,7 +67,11 @@ def _upstream_failure(method: str, path: str, resp: httpx.Response) -> YouTubeEr
     response at all is `_send`'s, with the reason `transport`.) The body is logged only under
     the requesting user's own Teljes consent: it is the request quoted back."""
     reason = _error_reason(resp)
-    log.warning(
+    # A reason the caller named as an answer rather than a failure (`channelNotFound` on a `mine`
+    # read: the account simply has no channel) is still raised, but it is not a warning — it came
+    # back every six hours for an account that will never have one.
+    log.log(
+        logging.DEBUG if reason in expected else logging.WARNING,
         "YouTube %s %s -> %s (%s)",
         method,
         path,
@@ -80,7 +92,45 @@ def _upstream_failure(method: str, path: str, resp: httpx.Response) -> YouTubeEr
             # log-pii-ok: only under this user's own Teljes consent, which is what it is for
             extra=logs.event("youtube.api.body", body=resp.text[:500]),
         )
-    return YouTubeError(f"{method} {path} -> {resp.status_code}: {reason}", reason=reason)
+    return YouTubeError(
+        f"{method} {path} -> {resp.status_code}: {reason}", reason=reason, path=path
+    )
+
+
+# The `mine` reads' answer for a Google account that has no YouTube channel.
+_NO_CHANNEL = frozenset({"channelNotFound"})
+
+# The reasons that mean the project's quota is spent: every further call today gets the same answer.
+_QUOTA_REASONS = frozenset({"quotaExceeded", "dailyLimitExceeded"})
+
+
+def is_quota_refusal(exc: YouTubeError) -> bool:
+    """Whether the API refused for want of quota. `reason` can list several codes, comma-joined."""
+    return any(r in _QUOTA_REASONS for r in exc.reason.split(","))
+
+
+# The token endpoint's answer for a revoked or expired grant — the one refusal a reconnect fixes.
+_DEAD_GRANT = "invalid_grant"
+
+# What a refused YouTube action means to the person who asked for it — the three things they can
+# act on differently: wait for tomorrow's budget, reconnect the account, or try again later.
+YouTubeRefusal = Literal["quota", "reconnect", "unavailable"]
+
+
+def refusal_reason(exc: YouTubeError) -> YouTubeRefusal:
+    """Sort a failure by what the user can do about it. A dead grant (Google refused the refresh
+    with `invalid_grant`, which also drops the grant — see `_drop_dead_grant`) or no usable token at
+    all (raised before any endpoint answered, so with no path and no transport reason) means the
+    account must be reconnected; retrying cannot help. Any other token-endpoint failure — a 5xx, a
+    429, a misconfigured client — leaves the grant as it was: reconnecting would not fix it, and
+    the account would still read as connected, with no connect button to press."""
+    if is_quota_refusal(exc):
+        return "quota"
+    if exc.path == "oauth2/token":
+        return "reconnect" if exc.reason == _DEAD_GRANT else "unavailable"
+    if not exc.path and exc.reason != "transport":
+        return "reconnect"
+    return "unavailable"
 
 
 def _chunks(items: list, size: int) -> Iterator[list]:
@@ -156,7 +206,10 @@ class YouTubeClient:
             },
         )
         if resp.status_code != 200:
-            raise _upstream_failure("POST", "oauth2/token", resp)
+            exc = _upstream_failure("POST", "oauth2/token", resp)
+            if exc.reason == _DEAD_GRANT:
+                self._drop_dead_grant(tok)
+            raise exc
         data = resp.json()
         access = data["access_token"]
         tok.access_token = encrypt(access)
@@ -166,8 +219,34 @@ class YouTubeClient:
         log.info("Refreshed access token for user %s", self.user.id)
         return access
 
+    def _drop_dead_grant(self, tok) -> None:
+        """Google answered the refresh with `invalid_grant`: the grant was revoked or expired, and no
+        retry will revive it. Forget it, so the account reads as NOT connected — Settings and the
+        onboarding wizard then offer the connect button again (a fresh consent issues a new refresh
+        token). Kept as "granted", the UI showed a live connection with no way to renew it while
+        every call failed. Committed like the refresh above: the caller rolls back on the error."""
+        tok.scopes = None
+        tok.access_token = None
+        tok.refresh_token_enc = None
+        tok.expiry = None
+        self.db.add(tok)
+        self.db.commit()
+        # INFO: the refusal itself is already the warning (`youtube.api.error`, invalid_grant).
+        log.info(
+            "cleared the dead YouTube grant of user %s",
+            self.user.id,
+            extra=logs.event("youtube.grant.cleared"),
+        )
+
     # --- core request ---
-    def _get(self, path: str, params: dict, cost: int = 1, allow_key: bool = True) -> dict:
+    def _get(
+        self,
+        path: str,
+        params: dict,
+        cost: int = 1,
+        allow_key: bool = True,
+        expected: frozenset[str] = frozenset(),
+    ) -> dict:
         p = dict(params)
         headers = {}
         api_key = sysconfig.get_str(self.db, "youtube_api_key")
@@ -178,7 +257,7 @@ class YouTubeClient:
         resp = self._send("GET", f"{API_BASE}/{path}", params=p, headers=headers)
         quota.record_usage(cost)
         if resp.status_code != 200:
-            raise _upstream_failure("GET", path, resp)
+            raise _upstream_failure("GET", path, resp, expected)
         return resp.json()
 
     # --- endpoints ---
@@ -218,7 +297,14 @@ class YouTubeClient:
             params = {"part": "snippet,contentDetails", "mine": "true", "maxResults": 50}
             if page_token:
                 params["pageToken"] = page_token
-            data = self._get("playlists", params, cost=1, allow_key=False)
+            try:
+                data = self._get("playlists", params, cost=1, allow_key=False, expected=_NO_CHANNEL)
+            except YouTubeError as exc:
+                # A Google account without a YouTube channel has no playlists, and YouTube says
+                # so as a 404. That is an empty list, not a failed sync.
+                if exc.reason in _NO_CHANNEL:
+                    return
+                raise
             for item in data.get("items", []):
                 sn = item.get("snippet", {})
                 yield {

backend/app/youtube/rss.py

@@ -1,6 +1,7 @@
 """Free per-channel RSS feed reader (no API quota). Returns the channel's most recent
 ~15 uploads as lightweight stubs for fast fresh-video detection."""
 
+import time
 from datetime import datetime, timezone
 
 import feedparser
@@ -8,6 +9,18 @@ import httpx
 
 RSS_URL = "https://www.youtube.com/feeds/videos.xml?channel_id={channel_id}"
 
+# The waits before a second and a third try. YouTube's feed endpoint answers the SAME channel with
+# 404, 500 and 200 in turn (measured 2026-09-19: 15 of 24 channels failed a first request, 16 of them
+# had succeeded by the fifth, one second apart), so one failure is not an answer. A feed that is
+# really gone costs two more requests per poll. A TIMEOUT is not tried again: the flaky endpoint
+# answers fast, and a request that hung for `TIMEOUT` says the way out is hanging — three of them
+# per channel would stretch a poll over a dead egress to three times its interval.
+RETRY_DELAYS = (1.0, 2.0)
+TIMEOUT = 20.0
+# A 404 is in the set because that is how the flaky endpoint fails most often; a 403/410 is not,
+# and neither is anything else that says the request itself is wrong.
+_RETRYABLE_STATUS = frozenset({404, 429, 500, 502, 503, 504})
+
 
 class RssError(Exception):
     """The feed could not be read (transport failure or a non-200 answer).
@@ -24,21 +37,36 @@ class RssError(Exception):
         self.reason = reason
 
 
-def fetch_channel_feed(channel_id: str) -> list[dict]:
-    """The channel's recent uploads as stubs. `[]` means the feed really is empty; a failure
-    raises RssError so the caller can leave the channel un-stamped and log it."""
+def _get_feed(channel_id: str) -> bytes:
+    """The feed's body, after up to `1 + len(RETRY_DELAYS)` tries; the LAST failure is raised."""
     url = RSS_URL.format(channel_id=channel_id)
-    try:
-        resp = httpx.get(url, timeout=20.0, headers={"User-Agent": "Siftlode/1.0"})
-    except httpx.HTTPError as exc:
-        raise RssError(f"RSS fetch failed for {channel_id}: {exc}", "transport") from exc
-    if resp.status_code != 200:
-        raise RssError(
+    for attempt in range(len(RETRY_DELAYS) + 1):
+        if attempt:
+            time.sleep(RETRY_DELAYS[attempt - 1])
+        try:
+            resp = httpx.get(url, timeout=TIMEOUT, headers={"User-Agent": "Siftlode/1.0"})
+        # silent-ok: not silent — the last failure is raised after the final try.
+        except httpx.HTTPError as exc:
+            error = RssError(f"RSS fetch failed for {channel_id}: {exc}", "transport")
+            error.__cause__ = exc
+            if isinstance(exc, httpx.TimeoutException):
+                break
+            continue
+        if resp.status_code == 200:
+            return resp.content
+        error = RssError(
             f"RSS fetch for {channel_id} returned HTTP {resp.status_code}",
             f"http_{resp.status_code}",
         )
+        if resp.status_code not in _RETRYABLE_STATUS:
+            break
+    raise error
 
-    parsed = feedparser.parse(resp.content)
+
+def fetch_channel_feed(channel_id: str) -> list[dict]:
+    """The channel's recent uploads as stubs. `[]` means the feed really is empty; a failure
+    (after the retries) raises RssError so the caller can leave the channel un-stamped and log it."""
+    parsed = feedparser.parse(_get_feed(channel_id))
     out: list[dict] = []
     for entry in parsed.entries:
         video_id = entry.get("yt_videoid")

backend/tests/conftest.py

@@ -21,7 +21,8 @@ from alembic import command
 from alembic.config import Config
 from fastapi import HTTPException, Request
 from fastapi.testclient import TestClient
-from sqlalchemy import create_engine, text
+from sqlalchemy import create_engine, event, text
+from starlette.requests import HTTPConnection
 
 import app.models  # noqa: F401 — register every model on Base.metadata
 import app.state as app_state
@@ -100,17 +101,67 @@ def pytest_configure(config):
         )
 
 
+def _request_dep(db, unfinished: list[str]):
+    """`get_db` for a test request: the test's own session, plus the check a shared session hides.
+
+    A route helper flushes and its HANDLER commits (CLAUDE.md). Production's `get_db` closes the
+    session after the request, which rolls back anything flushed but not committed — yet here every
+    request shares the test's session, so a follow-up GET or an assertion reads the flushed write
+    and the suite stays green over a handler that forgot to commit (deep review, debt burn). So a
+    request that ends normally with a write it did not commit — flushed, or still only staged — is
+    recorded, and the test fails on it at teardown. Only the ROOT transaction's end clears it: a
+    savepoint released inside the handler commits nothing. The test's own staged rows are flushed before the request starts — they are the
+    test's business, not the handler's. A request that raises is rolled back, as production's
+    `close()` rolls it back: without that, what a failing handler flushed but never committed stayed
+    readable to the rest of the test — the one state production cannot be in (E16: an issue created
+    on the tracker before a failed upload was kept only by an explicit commit, and nothing saw it
+    missing)."""
+
+    def dep(conn: HTTPConnection):
+        db.flush()
+        state = {"dirty": False}
+
+        def flushed(session, ctx):
+            state["dirty"] = True
+
+        def ended(session, transaction):
+            if transaction.parent is None:
+                state["dirty"] = False
+
+        hooks = (("after_flush", flushed), ("after_transaction_end", ended))
+        for name, fn in hooks:
+            event.listen(db, name, fn)
+        try:
+            yield db
+            staged = db.new or db.deleted or any(db.is_modified(o) for o in db.dirty)
+            if state["dirty"] or staged:
+                unfinished.append(f"{conn.scope.get('method', 'WS')} {conn.url.path}")
+        except Exception:
+            db.rollback()
+            raise
+        finally:
+            for name, fn in hooks:
+                event.remove(db, name, fn)
+
+    return dep
+
+
 @pytest.fixture
 def db(_schema):
     """A real session against the test Postgres, on a clean (empty) database. The code under test
-    may commit freely."""
+    may commit freely. `db.info["request"]` is the `get_db` override for a request against it — the
+    one every test client uses — and a handler that left a write uncommitted fails the test here."""
     _truncate_all()
     session = SessionLocal()
+    unfinished: list[str] = []
+    session.info["request"] = _request_dep(session, unfinished)
+    session.info["unfinished"] = unfinished  # the requests recorded so far (the check's own test)
     try:
         yield session
     finally:
         session.rollback()
         session.close()
+    assert unfinished == [], "a handler left a write uncommitted"
 
 
 @pytest.fixture
@@ -168,7 +219,7 @@ def client(db, override_dep, _configured):
     `current_user` override — so login, the wallet gate and epoch revoke are exercised end to end.
     Starlette's SessionMiddleware round-trips the signed cookie, so a login in one call authenticates
     the next on this same instance. No lifespan (the scheduler / HLS sweep stay off)."""
-    override_dep(get_db, lambda: db)
+    override_dep(get_db, db.info["request"])
     return TestClient(app)
 
 
@@ -187,7 +238,7 @@ def as_user(db, override_dep, _configured):
             raise HTTPException(status_code=401, detail="Not authenticated")
         return registry[uid]
 
-    override_dep(get_db, lambda: db)
+    override_dep(get_db, db.info["request"])
     override_dep(current_user, _resolver)
 
     def _as(user: User) -> TestClient:

backend/tests/test_admin_invites.py

@@ -168,3 +168,15 @@ def test_deleting_the_user_also_clears_the_way_to_re_invite(db, make_user, as_us
     assert (
         db.execute(select(Invite).where(Invite.email == member.email)).scalar_one_or_none() is None
     )
+
+
+def test_whitelisting_a_new_address_audits_it_by_id(db, make_user, as_user):
+    """The audit row was written before the new invite had an id, so it named no target."""
+    from app.models import AuditLog
+
+    admin = make_user(role="admin")
+    r = as_user(admin).post("/api/admin/invites", json={"email": "fresh-e27@example.com"})
+    assert r.status_code == 200
+    inv = db.scalar(select(Invite).where(Invite.email == "fresh-e27@example.com"))
+    row = db.scalar(select(AuditLog).where(AuditLog.target_type == "invite"))
+    assert row is not None and row.target_id == str(inv.id)

backend/tests/test_admin_logs.py

@@ -0,0 +1,191 @@
+"""The admin diagnostics console's query API (E22.6 S1), DB-lane."""
+
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from sqlalchemy import insert
+
+from app.models import LogEvent
+
+T0 = datetime(2026, 9, 19, 12, 0, tzinfo=timezone.utc)
+
+
+def _row(**kw) -> dict:
+    row = {
+        "ts": T0,
+        "level": "INFO",
+        "sev": 9,
+        "source": "api",
+        "logger": "siftlode.http",
+        "event": "http.request",
+        "msg": "GET /api/feed 200",
+        "attrs": None,
+        "exc": None,
+        "request_id": None,
+        "user_id": None,
+        "job_id": None,
+        "version": "0.90.0",
+    }
+    row.update(kw)
+    return row
+
+
+def _add(db, *rows: dict) -> None:
+    db.execute(insert(LogEvent), list(rows))
+    db.commit()
+
+
+@pytest.fixture
+def admin(db, make_user, as_user):
+    return as_user(make_user(email="admin@example.com", role="admin"))
+
+
+def _msgs(resp) -> list[str]:
+    assert resp.status_code == 200, resp.text
+    return [it["msg"] for it in resp.json()["items"]]
+
+
+def test_only_an_admin_reads_the_log(db, make_user, as_user, client):
+    _add(db, _row())
+    assert as_user(make_user()).get("/api/admin/logs").status_code == 403
+    assert as_user(make_user()).get("/api/admin/logs/facets").status_code == 403
+    assert client.get("/api/admin/logs").status_code == 401
+
+
+def test_newest_first_and_every_row_once_across_pages_even_on_equal_timestamps(db, admin):
+    # A browser row's `ts` is clamped, so several rows share one: the id breaks the tie.
+    _add(db, *[_row(msg=f"same {i}") for i in range(5)], _row(ts=T0 - timedelta(1), msg="older"))
+
+    seen, cursor = [], None
+    while True:
+        resp = admin.get(
+            "/api/admin/logs", params={"limit": 2, "before": cursor} if cursor else {"limit": 2}
+        )
+        seen += _msgs(resp)
+        cursor = resp.json()["next_cursor"]
+        if cursor is None:
+            break
+
+    assert seen == ["same 4", "same 3", "same 2", "same 1", "same 0", "older"]
+
+
+@pytest.mark.parametrize(
+    ("params", "expected"),
+    [
+        ({"levels": ["ERROR", "WARNING"]}, {"err", "warn"}),
+        ({"sources": ["worker"]}, {"err"}),
+        ({"user": "1"}, {"mine"}),
+        ({"user": "none"}, {"err", "warn", "plain"}),
+        ({"event": "download.job.failed"}, {"err"}),
+        ({"event": "none"}, {"warn"}),
+        ({"request_id": "req-abcdef12"}, {"mine"}),
+        ({"job_id": 42}, {"err"}),
+        ({"q": "FORBIDDEN"}, {"err"}),  # in attrs, any case
+        ({"q": "KeyError"}, {"warn"}),  # in the stack
+        ({"q": "100%"}, {"plain"}),  # a literal, not a wildcard
+        ({"since": (T0 - timedelta(hours=1)).isoformat()}, {"mine", "err", "warn"}),
+        ({"until": (T0 - timedelta(hours=1)).isoformat()}, {"plain", "decoy"}),
+        ({"levels": ["INFO"], "user": "none"}, {"plain"}),
+    ],
+)
+def test_each_filter_selects_exactly_its_rows(db, admin, make_user, params, expected):
+    # user 1 is the admin the fixture made
+    _add(
+        db,
+        _row(msg="mine", user_id=1, request_id="req-abcdef12"),
+        _row(
+            msg="err",
+            level="ERROR",
+            sev=17,
+            source="worker",
+            event="download.job.failed",
+            job_id=42,
+            attrs={"code": "forbidden"},
+        ),
+        _row(msg="warn", level="WARNING", sev=13, event=None, exc="Traceback …\nKeyError: 'x'"),
+        _row(msg="plain", ts=T0 - timedelta(hours=2), attrs={"note": "100% done"}),
+        # Matched by no filter above but `until`: another account, and `100%` read as a pattern.
+        _row(msg="decoy", ts=T0 - timedelta(hours=3), attrs={"note": "1000 done"}, user_id=99),
+    )
+    assert set(_msgs(admin.get("/api/admin/logs", params=params))) == expected
+
+
+def test_a_page_names_its_accounts_and_leaves_an_erased_one_bare(db, admin):
+    _add(db, _row(user_id=1), _row(user_id=77))
+
+    assert admin.get("/api/admin/logs").json()["accounts"] == {"1": "admin@example.com"}
+
+
+@pytest.mark.parametrize(
+    "params",
+    [
+        {"before": "not-a-cursor"},
+        {"before": "WyJ4IiwgMV0="},  # ["x", 1]: decodes, not a timestamp
+    ],
+)
+def test_a_bad_cursor_is_a_400_with_a_code(db, admin, params):
+    resp = admin.get("/api/admin/logs", params=params)
+    assert resp.status_code == 400
+    assert resp.json()["detail"]["code"] == "bad_cursor"
+
+
+def test_facets_count_the_window_and_name_the_rows_without_a_value(db, admin):
+    _add(
+        db,
+        _row(user_id=1),
+        _row(user_id=1, level="ERROR", sev=17, event="sync.rss.failed"),
+        _row(event=None),
+        _row(ts=T0 - timedelta(days=2), source="worker"),
+    )
+
+    body = admin.get(
+        "/api/admin/logs/facets", params={"since": (T0 - timedelta(days=1)).isoformat()}
+    ).json()
+
+    assert body["total"] == 3
+    assert body["levels"] == [{"value": "INFO", "count": 2}, {"value": "ERROR", "count": 1}]
+    assert body["sources"] == [{"value": "api", "count": 3}]
+    assert body["events"] == [
+        {"value": "http.request", "count": 1},
+        {"value": "sync.rss.failed", "count": 1},
+        {"value": "none", "count": 1},
+    ]
+    assert body["users"] == [{"value": "1", "count": 2}, {"value": "none", "count": 1}]
+    assert body["accounts"] == {"1": "admin@example.com"}
+
+
+def test_a_facet_counts_under_every_other_filter_but_not_its_own(db, admin):
+    _add(
+        db,
+        _row(request_id="req-aaaaaaaa"),
+        _row(request_id="req-aaaaaaaa", level="ERROR", sev=17, source="worker"),
+        _row(request_id="req-bbbbbbbb", level="ERROR", sev=17),
+        _row(request_id="req-bbbbbbbb"),
+    )
+
+    body = admin.get(
+        "/api/admin/logs/facets", params={"request_id": "req-aaaaaaaa", "levels": ["ERROR"]}
+    ).json()
+
+    # The pivot narrows every count; the picked level does not zero its sibling (the way back).
+    assert body["levels"] == [{"value": "ERROR", "count": 1}, {"value": "INFO", "count": 1}]
+    assert body["total"] == 2
+    # Every other facet counts under the level filter too.
+    assert body["sources"] == [{"value": "worker", "count": 1}]
+
+
+@pytest.mark.parametrize(
+    ("params", "facet", "expected"),
+    [
+        ({"sources": ["worker"]}, "sources", {"api", "worker"}),
+        ({"user": "1"}, "users", {"1", "none"}),
+        ({"event": "sync.rss.failed"}, "events", {"http.request", "sync.rss.failed"}),
+    ],
+)
+def test_every_facet_keeps_its_siblings_under_its_own_filter(db, admin, params, facet, expected):
+    # The way back from a pick: the picked facet still offers the values it was picked from.
+    _add(db, _row(user_id=1), _row(source="worker", event="sync.rss.failed"))
+
+    body = admin.get("/api/admin/logs/facets", params=params).json()
+
+    assert {f["value"] for f in body[facet]} == expected

backend/tests/test_auth_session.py

@@ -447,7 +447,7 @@ def test_register_route_creates_the_account_end_to_end(client, db, monkeypatch):
 
     r = client.post("/auth/register", json={"email": "newbie@example.com", "password": _PW})
 
-    assert r.status_code == 200 and r.json() == {"status": "ok"}
+    assert r.status_code == 200 and r.json() == {"ok": True, "status": "ok"}
     db.expire_all()
     user = db.execute(_select(User).where(User.email == "newbie@example.com")).scalar_one_or_none()
     assert user is not None, "POST /auth/register answered ok but created nothing"

backend/tests/test_channel_backfill.py

@@ -18,7 +18,7 @@ from app.sync import runner, videos
 _PUB = datetime(2020, 1, 1, tzinfo=timezone.utc)
 
 
-def test_channel_detail_returns_normal_shorts_live_counts(db, monkeypatch):
+def test_channel_detail_returns_normal_shorts_live_counts(db, monkeypatch, override_dep):
     # published_at set so channel_detail skips the YouTube-enrich path (no quota / network in tests).
     ch = Channel(id="UC_nsl", title="N/S/L Channel", published_at=_PUB)
     db.add(ch)
@@ -40,12 +40,9 @@ def test_channel_detail_returns_normal_shorts_live_counts(db, monkeypatch):
 
     # The request gate 503s an unconfigured instance; flip the process-level flag (auto-restored).
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: me
-    try:
-        resp = TestClient(app).get(f"/api/channels/{ch.id}")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: me)
+    resp = TestClient(app).get(f"/api/channels/{ch.id}")
 
     assert resp.status_code == 200, resp.text
     body = resp.json()
@@ -56,7 +53,7 @@ def test_channel_detail_returns_normal_shorts_live_counts(db, monkeypatch):
 
 
 @pytest.mark.parametrize("hidden", [True, False])
-def test_channel_detail_surfaces_subscription_hidden_flag(db, monkeypatch, hidden):
+def test_channel_detail_surfaces_subscription_hidden_flag(db, monkeypatch, hidden, override_dep):
     # S6: the detail GET must expose the per-subscription `hidden` flag so the channel page can offer
     # the same Unhide toggle the manager has (the flag was previously omitted from the detail dict).
     ch = Channel(id="UC_hid", title="Hidden?", published_at=_PUB)
@@ -68,18 +65,15 @@ def test_channel_detail_surfaces_subscription_hidden_flag(db, monkeypatch, hidde
     db.commit()
 
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: me
-    try:
-        resp = TestClient(app).get(f"/api/channels/{ch.id}")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: me)
+    resp = TestClient(app).get(f"/api/channels/{ch.id}")
 
     assert resp.status_code == 200, resp.text
     assert resp.json()["hidden"] is hidden
 
 
-def test_channel_detail_hidden_defaults_false_when_not_subscribed(db, monkeypatch):
+def test_channel_detail_hidden_defaults_false_when_not_subscribed(db, monkeypatch, override_dep):
     # No subscription row → the flag can't be True; it must serialize as False, not raise.
     ch = Channel(id="UC_hid_ns", title="Unsub", published_at=_PUB)
     me = User(email="hidns@example.com")
@@ -87,12 +81,9 @@ def test_channel_detail_hidden_defaults_false_when_not_subscribed(db, monkeypatc
     db.commit()
 
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: me
-    try:
-        resp = TestClient(app).get(f"/api/channels/{ch.id}")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: me)
+    resp = TestClient(app).get(f"/api/channels/{ch.id}")
 
     assert resp.status_code == 200, resp.text
     assert resp.json()["hidden"] is False
@@ -115,33 +106,30 @@ def _setup_channel_and_sub(db, *, email, is_demo=False):
     return ch, user
 
 
-def _patch_deep_requested(db, monkeypatch, user):
+def _patch_deep_requested(db, monkeypatch, override_dep, user):
     calls: list[tuple] = []
     # background.add_task runs after the response in TestClient; record what would be scheduled.
     monkeypatch.setattr(channels_route, "backfill_channel_now", lambda *a, **k: calls.append(a))
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        resp = TestClient(app).patch("/api/channels/UC_wire", json={"deep_requested": True})
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    resp = TestClient(app).patch("/api/channels/UC_wire", json={"deep_requested": True})
     return resp, calls
 
 
-def test_deep_request_schedules_immediate_backfill_for_non_demo(db, monkeypatch):
+def test_deep_request_schedules_immediate_backfill_for_non_demo(db, monkeypatch, override_dep):
     ch, me = _setup_channel_and_sub(db, email="wire@example.com")
-    resp, calls = _patch_deep_requested(db, monkeypatch, me)
+    resp, calls = _patch_deep_requested(db, monkeypatch, override_dep, me)
     assert resp.status_code == 200, resp.text
     assert resp.json()["deep_requested"] is True
     # scheduled exactly once, with (channel_id, user_id) — the args backfill_channel_now needs.
     assert calls == [(ch.id, me.id)]
 
 
-def test_deep_request_does_not_schedule_immediate_backfill_for_demo(db, monkeypatch):
+def test_deep_request_does_not_schedule_immediate_backfill_for_demo(db, monkeypatch, override_dep):
     # The SHARED demo account must not be able to kick immediate full backfills (budget drain).
     _ch, demo = _setup_channel_and_sub(db, email="demo@example.com", is_demo=True)
-    resp, calls = _patch_deep_requested(db, monkeypatch, demo)
+    resp, calls = _patch_deep_requested(db, monkeypatch, override_dep, demo)
     assert resp.status_code == 200, resp.text
     assert calls == [], "demo must not schedule an immediate backfill"
     # …and deep_requested is not persisted on the shared demo subscription either.

backend/tests/test_channel_tags.py

@@ -17,7 +17,7 @@ from app.main import app
 from app.models import Channel, ChannelTag, Tag, User
 
 
-def test_channel_detail_returns_only_this_users_tag_ids(db, monkeypatch):
+def test_channel_detail_returns_only_this_users_tag_ids(db, monkeypatch, override_dep):
     # published_at set so channel_detail skips the YouTube-enrich path (no quota / network in tests).
     ch = Channel(
         id="UC_tags_test",
@@ -43,13 +43,10 @@ def test_channel_detail_returns_only_this_users_tag_ids(db, monkeypatch):
 
     # The request gate 503s an unconfigured instance; flip the process-level flag (auto-restored).
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: me
-    try:
-        client = TestClient(app)  # no context-manager: skip lifespan (scheduler/HLS sweep)
-        resp = client.get(f"/api/channels/{ch.id}")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: me)
+    client = TestClient(app)  # no context-manager: skip lifespan (scheduler/HLS sweep)
+    resp = client.get(f"/api/channels/{ch.id}")
 
     assert resp.status_code == 200, resp.text
     assert resp.json()["tag_ids"] == [mine.id]

backend/tests/test_diagnostics.py

@@ -68,6 +68,7 @@ def test_raising_the_level_sets_the_servers_expiry_whatever_the_client_sends(db,
         "level": "INFO",
         "until": None,
         "retention_days": 7,
+        "session_minutes": 60,
     }
 
 
@@ -82,6 +83,7 @@ def test_a_lapsed_level_reads_as_the_base_in_me(db, client, make_user):
         "level": "INFO",
         "until": None,
         "retention_days": 7,
+        "session_minutes": 60,
     }
 
 

backend/tests/test_discover.py

@@ -544,6 +544,73 @@ def test_shelf_resolves_a_playlist_to_its_first_unwatched_item(db):
     assert card["next"]["id"] == "vmed"
 
 
+def _count_statements(db, fn) -> int:
+    """How many SQL statements `fn` sends through the session's connection."""
+    from sqlalchemy import event
+
+    seen: list[str] = []
+    engine = db.get_bind()
+    listener = lambda *a, **k: seen.append(a[2])  # noqa: E731 — (conn, cursor, statement, …)
+    event.listen(engine, "before_cursor_execute", listener)
+    try:
+        fn()
+    finally:
+        event.remove(engine, "before_cursor_execute", listener)
+    return len(seen)
+
+
+def test_the_shelf_resolves_each_channel_and_playlist_on_its_own_terms(db):
+    """Batched, the per-channel count and newest video come from one windowed query: each channel
+    must still get ITS count and ITS newest, not the shelf's overall first row."""
+    user, ch = _seed_yt(db)
+    other = Channel(id="UCother", title="Other")
+    db.add(other)
+    db.flush()
+    db.add(Video(id="vother", channel_id=other.id, title="x", published_at=NOW - timedelta(days=9)))
+    pl = Playlist(user_id=user.id, name="Két elem")
+    empty = Playlist(user_id=user.id, name="Üres")
+    db.add_all([pl, empty])
+    db.flush()
+    db.add(PlaylistItem(playlist_id=pl.id, video_id="vlong", position=0))
+    for i, target in enumerate(
+        [
+            {"channel_id": ch.id},
+            {"channel_id": other.id},
+            {"playlist_id": pl.id},
+            {"playlist_id": empty.id},
+        ]
+    ):
+        db.add(ComfortPin(user_id=user.id, position=i, **target))
+    db.commit()
+
+    got = [
+        (c.get("unwatched_count", c.get("item_count")), (c["next"] or {}).get("id"))
+        for c in pins.shelf(db, user)
+    ]
+    assert got == [(3, "vshort"), (1, "vother"), (1, "vlong"), (0, None)]
+
+
+def test_the_shelf_costs_the_same_queries_for_one_pin_or_many(db):
+    """A channel pin used to cost three queries and a playlist pin two, each; the shelf now
+    resolves every channel and every playlist together."""
+    user, ch = _seed_yt(db)
+    extra = [Channel(id=f"UCx{i}", title=f"x{i}") for i in range(3)]
+    lists = [Playlist(user_id=user.id, name=f"p{i}") for i in range(4)]
+    db.add_all(extra + lists)
+    db.flush()
+    db.add(ComfortPin(user_id=user.id, channel_id=ch.id, position=0))
+    db.add(ComfortPin(user_id=user.id, playlist_id=lists[0].id, position=1))
+    db.commit()
+    few = _count_statements(db, lambda: pins.shelf(db, user))
+
+    for i, c in enumerate(extra):
+        db.add(ComfortPin(user_id=user.id, channel_id=c.id, position=10 + i))
+    for i, p in enumerate(lists[1:]):
+        db.add(ComfortPin(user_id=user.id, playlist_id=p.id, position=20 + i))
+    db.commit()
+    assert _count_statements(db, lambda: pins.shelf(db, user)) == few
+
+
 def test_a_pinned_video_survives_leaving_the_feed_scope(db):
     """The shelf is the fallback surface. An entry silently vanishing because the user unsubscribed
     from the channel is exactly the failure it must not have."""
@@ -940,3 +1007,115 @@ def test_deleting_a_pin_reports_what_went(db, as_user):
     r = c.delete(f"/api/discover/pins/{pin_id}")
     assert r.status_code == 200 and r.json() == {"deleted": pin_id}
     assert c.get("/api/discover/pins").json()["items"] == []
+
+
+def test_with_plex_off_the_home_shelf_hides_plex_pins_but_keeps_them(db, as_user):
+    """The owner's call (2026-09-19): with the deployment's Plex toggle off, the Home shelf goes
+    YouTube-only like the rails beside it — a Plex tile there offered a Play that landed on a gated
+    module. The hero's comfort tier draws from the same filtered shelf, and the pin menus' own
+    listing still sees every pin, so nothing the user curated is lost."""
+    user, _ = _seed_yt(db)
+    _seed_plex(db, user)
+    db.add_all(
+        [
+            ComfortPin(
+                user_id=user.id,
+                plex_item_id=db.scalar(select(PlexItem.id).where(PlexItem.rating_key == "pm1")),
+                position=0,
+            ),
+            ComfortPin(user_id=user.id, video_id="vlong", position=1),
+        ]
+    )
+    db.commit()
+    c = as_user(user)
+    assert [t["id"] for t in c.get("/api/discover").json()["comfort"]] == ["vlong"]
+    assert c.get("/api/discover/pick?start=1").json()["hero"]["card"]["id"] == "vlong"
+    assert {t["id"] for t in c.get("/api/discover/pins").json()["items"]} == {"pm1", "vlong"}
+    _enable_plex(db)
+    assert [t["id"] for t in c.get("/api/discover").json()["comfort"]] == ["pm1", "vlong"]
+
+
+def test_a_reorder_of_the_visible_pins_keeps_the_hidden_ones_in_place(db, as_user):
+    """The client sends the order it SHOWS. With Plex off that leaves the Plex pins out, and
+    numbering only the listed ids 0..n-1 put two pins on one position and moved the hidden one about
+    when Plex came back. The listed pins trade the slots they hold; the rest stay put."""
+    user, ch = _seed_yt(db)
+    _seed_plex(db, user)
+    c = as_user(user)
+    _enable_plex(db)
+    a = c.post("/api/discover/pins", json={"kind": "video", "ref": "vmed"}).json()["id"]
+    hidden = c.post("/api/discover/pins", json={"kind": "plex_item", "ref": "pm1"}).json()["id"]
+    b = c.post("/api/discover/pins", json={"kind": "channel", "ref": ch.id}).json()["id"]
+    assert c.post("/api/discover/pins/reorder", json={"ids": [b, b, a]}).status_code == 200
+    assert [p["pin_id"] for p in c.get("/api/discover/pins").json()["items"]] == [b, hidden, a]
+    positions = db.scalars(select(ComfortPin.position).where(ComfortPin.user_id == user.id)).all()
+    assert sorted(positions) == [0, 1, 2]
+
+
+def test_a_hero_from_a_show_pin_names_the_pin_it_came_from(db, as_user):
+    """A show's next EPISODE is not itself pinned, so the hero's menu used to look the episode up,
+    miss, and offer "Pin" under "From your shelf" — creating a second pin. The card now carries
+    the pin it was resolved from, which the menu acts on (owner's call: "Unpin")."""
+    user, _ = _seed_yt(db)
+    _seed_plex(db, user)
+    _enable_plex(db)
+    c = as_user(user)
+    assert c.post("/api/discover/pins", json={"kind": "plex_show", "ref": "ps1"}).status_code == 200
+    got = c.get("/api/discover/pick?start=1").json()["hero"]
+    assert got["tier"] == "comfort" and got["card"]["id"] == "ps1e1"
+    assert got["card"]["pinned_from"] == {
+        "source": "plex",
+        "kind": "show",
+        "id": "ps1",
+        "title": "A Show",
+    }
+
+
+def test_two_overlapping_reorders_never_share_a_slot(db, as_user):
+    """`reorder` writes only the rows that change. Unlocked, two tabs reordering from the same
+    snapshot each skipped the rows that already matched in THEIR snapshot and interleaved row by
+    row — two pins on one slot (deep review, debt burn). Locked, the second waits for the first and
+    deals from its result: here a partial list (a tab with Plex off, one pin hidden), whose left-out
+    pin must stay where the FIRST reorder put it — a lock taken in position order handed the waiter
+    fresh rows in its stale order, and it dealt that pin back to its old slot (round 2)."""
+    import threading
+
+    from app.db import SessionLocal
+
+    user, ch = _seed_yt(db)
+    c = as_user(user)
+    p1 = c.post("/api/discover/pins", json={"kind": "video", "ref": "vmed"}).json()["id"]
+    p2 = c.post("/api/discover/pins", json={"kind": "channel", "ref": ch.id}).json()["id"]
+    p3 = c.post("/api/discover/pins", json={"kind": "video", "ref": "vlong"}).json()["id"]
+    uid = user.id
+
+    with SessionLocal() as tab_a, SessionLocal() as tab_b, SessionLocal() as probe:
+        pins.reorder(tab_a, tab_a.get(User, uid), [p2, p3, p1])  # written, not yet committed
+        errors: list[BaseException] = []
+
+        def second_tab():
+            try:
+                pins.reorder(tab_b, tab_b.get(User, uid), [p3, p2])
+                tab_b.commit()
+            except BaseException as exc:  # noqa: BLE001 — re-raised in the test thread below
+                errors.append(exc)
+
+        worker = threading.Thread(target=second_tab)
+        worker.start()
+        # Commit A only once B is blocked on a row lock, so B's read is the stale snapshot.
+        waiting = 0
+        for _ in range(200):
+            waiting = probe.scalar(text("SELECT count(*) FROM pg_locks WHERE NOT granted"))
+            probe.rollback()
+            if waiting:
+                break
+            worker.join(0.05)
+        assert waiting, "tab B never blocked — the race was not exercised"
+        tab_a.commit()
+        worker.join(10)
+        assert not worker.is_alive() and errors == []
+
+    db.expire_all()
+    positions = db.scalars(select(ComfortPin.position).where(ComfortPin.user_id == uid)).all()
+    assert sorted(positions) == [0, 1, 2]
+    assert [p["pin_id"] for p in c.get("/api/discover/pins").json()["items"]] == [p3, p2, p1]

backend/tests/test_feed_cursor.py

@@ -15,34 +15,31 @@ from app.main import app
 from app.models import User
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(
         state, "_configured_cache", True
     )  # the request gate 503s an unconfigured app
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        client = TestClient(app)  # no context manager: skip lifespan (scheduler/HLS sweep)
-        return client.get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    client = TestClient(app)  # no context manager: skip lifespan (scheduler/HLS sweep)
+    return client.get(path)
 
 
-def test_malformed_feed_cursor_returns_400(db, monkeypatch):
+def test_malformed_feed_cursor_returns_400(db, monkeypatch, override_dep):
     user = User(email="feedcursor@example.com")
     db.add(user)
     db.commit()
-    resp = _get(db, user, monkeypatch, "/api/feed?cursor=not-a-real-cursor")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/feed?cursor=not-a-real-cursor")
     assert resp.status_code == 400
-    assert resp.json()["detail"] == "Invalid feed cursor"
+    assert resp.json()["detail"] == {"code": "refused", "reason": "invalid_cursor"}
 
 
-def test_feed_without_cursor_is_200(db, monkeypatch):
+def test_feed_without_cursor_is_200(db, monkeypatch, override_dep):
     # Sanity: the same endpoint without a cursor is a normal 200 (proves the 400 above is the
     # cursor path, not a globally-broken request). A fresh user has no subscriptions → empty feed.
     user = User(email="feednocursor@example.com")
     db.add(user)
     db.commit()
-    resp = _get(db, user, monkeypatch, "/api/feed")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/feed")
     assert resp.status_code == 200
     assert resp.json()["items"] == []

backend/tests/test_feed_fallback.py

@@ -0,0 +1,150 @@
+"""The RSS poll's API fallback (`sync/runner.run_feed_fallback`), DB-lane: which channels are read
+through the Data API when their feed stays dark, and how often."""
+
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+from app import sysconfig
+from app.models import Channel, Video
+from app.sync import runner
+from app.youtube.client import YouTubeError
+
+NOW = datetime.now(timezone.utc)
+_PUB = datetime(2020, 1, 1, tzinfo=timezone.utc)
+
+
+class _FakeYt:
+    # playlist id -> the reason its read fails with (the tests put entries here)
+    failing: dict[str, str] = {}
+
+    def __init__(self, calls):
+        self.calls = calls
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *exc):
+        return False
+
+    def get_playlist_items(self, playlist_id, page_token=None):
+        self.calls.append(playlist_id)
+        if playlist_id in self.failing:
+            reason = self.failing[playlist_id]
+            # A request that never got through has no endpoint that answered.
+            path = "" if reason == "transport" else "playlistItems"
+            raise YouTubeError("refused", reason=reason, path=path)
+        cid = "UC" + playlist_id[2:]
+        return {
+            "items": [
+                {
+                    "contentDetails": {"videoId": f"{cid}-v1", "videoPublishedAt": NOW.isoformat()},
+                    "snippet": {"title": "new upload"},
+                }
+            ]
+        }
+
+
+@pytest.fixture
+def calls(monkeypatch):
+    made: list[str] = []
+    monkeypatch.setattr(runner, "get_service_user", lambda db: object())
+    monkeypatch.setattr(runner, "YouTubeClient", lambda db, user: _FakeYt(made))
+    monkeypatch.setattr(runner.quota, "backfill_reserve_reached", lambda: False)
+    monkeypatch.setattr(_FakeYt, "failing", {})
+    return made
+
+
+def _channel(db, cid, *, rss=None, fallback=None, uploads=True):
+    ch = Channel(
+        id=cid,
+        title=cid,
+        published_at=_PUB,
+        uploads_playlist_id=("UU" + cid[2:]) if uploads else None,
+        last_rss_at=rss,
+        feed_fallback_at=fallback,
+    )
+    db.add(ch)
+    db.commit()
+    return ch
+
+
+def test_a_feed_dark_past_the_window_is_read_through_the_api(db, calls):
+    _channel(db, "UCdark", rss=NOW - timedelta(hours=3))
+
+    out = runner.run_feed_fallback(db, ["UCdark"])
+
+    assert out == {"read": 1, "new": 1, "failed": 0}
+    assert calls == ["UUdark"]
+    assert db.get(Video, "UCdark-v1") is not None
+    assert db.get(Channel, "UCdark").feed_fallback_at is not None
+
+
+@pytest.mark.parametrize(
+    ("rss", "fallback"),
+    [
+        (NOW - timedelta(minutes=30), None),  # the feed answered recently: a blip, not an outage
+        (NOW - timedelta(hours=5), NOW - timedelta(minutes=30)),  # already read this window
+    ],
+)
+def test_a_channel_read_within_the_window_is_left_alone(db, calls, rss, fallback):
+    _channel(db, "UCrecent", rss=rss, fallback=fallback)
+
+    assert runner.run_feed_fallback(db, ["UCrecent"])["read"] == 0
+    assert calls == []
+
+
+def test_the_window_is_the_admins_and_zero_turns_it_off(db, calls):
+    _channel(db, "UCdark", rss=NOW - timedelta(hours=3))
+
+    sysconfig.set_value(db, "rss_fallback_hours", 4)
+    db.commit()
+    assert runner.run_feed_fallback(db, ["UCdark"])["read"] == 0
+
+    sysconfig.set_value(db, "rss_fallback_hours", 0)
+    db.commit()
+    _channel(db, "UCnever")
+    assert runner.run_feed_fallback(db, ["UCdark", "UCnever"])["read"] == 0
+    assert calls == []
+
+
+def test_only_the_named_channels_and_only_those_with_an_uploads_playlist(db, calls):
+    _channel(db, "UCdark")
+    _channel(db, "UCother")
+    _channel(db, "UCnolist", uploads=False)
+
+    assert runner.run_feed_fallback(db, ["UCdark", "UCnolist"])["read"] == 1
+    assert calls == ["UUdark"]
+
+
+def test_it_yields_to_the_backfill_reserve(db, calls, monkeypatch):
+    _channel(db, "UCdark")
+    monkeypatch.setattr(runner.quota, "backfill_reserve_reached", lambda: True)
+
+    assert runner.run_feed_fallback(db, ["UCdark"])["read"] == 0
+    assert calls == []
+
+
+def test_a_read_that_fails_waits_the_window_out_too(db, calls):
+    # A terminated channel: its feed 404s and so does its uploads playlist, for good. Without a
+    # stamp it was charged on every 20-minute poll instead of once per window.
+    _channel(db, "UCgone", rss=NOW - timedelta(hours=3))
+    _FakeYt.failing["UUgone"] = "playlistNotFound"
+
+    assert runner.run_feed_fallback(db, ["UCgone"]) == {"read": 0, "new": 0, "failed": 1}
+    assert db.get(Channel, "UCgone").feed_fallback_at is not None
+    assert runner.run_feed_fallback(db, ["UCgone"])["failed"] == 0
+    assert calls == ["UUgone"]
+
+
+@pytest.mark.parametrize("reason", ["quotaExceeded", "transport"])
+def test_a_failure_not_about_the_channel_ends_the_round_and_costs_no_window(db, calls, reason):
+    # Out of quota, or no connection: every further channel would fail the same way, and a channel
+    # that was never answered about keeps its turn for the next poll.
+    _channel(db, "UCa")
+    _channel(db, "UCb")
+    _FakeYt.failing["UUa"] = reason
+
+    assert runner.run_feed_fallback(db, ["UCa", "UCb"])["failed"] == 1
+    assert calls == ["UUa"]
+    assert db.get(Channel, "UCa").feed_fallback_at is None

backend/tests/test_followed_channels.py

@@ -27,7 +27,7 @@ def test_the_rss_poll_skips_channels_nobody_follows(db, make_user, monkeypatch):
     polled: list[str] = []
     monkeypatch.setattr(runner, "fetch_channel_feed", lambda cid: polled.append(cid) or [])
     monkeypatch.setattr(runner, "apply_rss_feed", lambda db, ch, entries: 0)
-    assert runner.run_rss_poll(db) == {"new": 0, "failed": 0}
+    assert runner.run_rss_poll(db) == {"new": 0, "failed": 0, "fallback": 0}
     assert sorted(polled) == ["UC_explored", "UC_sub"]
 
 

backend/tests/test_hls_reaper.py

@@ -116,10 +116,10 @@ def test_the_periodic_pass_still_reaps_what_nobody_has_touched_for_the_idle_limi
 
 def test_touching_a_session_keeps_it_through_the_short_rule(tmp_path, sessions):
     s = _Session(tmp_path, "paused", finished=True, idle_s=90)
-    sessions["12345"] = s
-    stream.touch_session("12345")
+    sessions[(1, "12345")] = s
+    stream.touch_session(1, "12345")
     assert stream.reap_idle() == 0
-    assert "12345" in sessions and s.dir.exists() and not s.proc.killed
+    assert (1, "12345") in sessions and s.dir.exists() and not s.proc.killed
 
 
 # --- the two call sites, driven through the real routes (DB lane) -------------------------------
@@ -142,13 +142,15 @@ def _library_item(db, rating_key: str, *, playable: str = "remux"):
     return it
 
 
-def _client(db, user):
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
+def _client(db, user, override_dep):
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
     return TestClient(app)
 
 
-def test_a_paused_viewers_checkpoint_keeps_their_session_alive(db, monkeypatch, tmp_path, sessions):
+def test_a_paused_viewers_checkpoint_keeps_their_session_alive(
+    db, monkeypatch, tmp_path, sessions, override_dep
+):
     """The whole reason the short rule is safe again: a paused player fetches nothing, so
     `last_access` never moved on its own — but it does keep checkpointing its position."""
     monkeypatch.setattr(state, "_configured_cache", True)
@@ -157,21 +159,18 @@ def test_a_paused_viewers_checkpoint_keeps_their_session_alive(db, monkeypatch,
     db.add(user)
     db.commit()
     s = _Session(tmp_path, "paused", finished=True, idle_s=90)
-    sessions["paused1"] = s
-    try:
-        resp = _client(db, user).post(
-            f"/api/plex/item/{it.rating_key}/progress",
-            json={"position_seconds": 600, "duration_seconds": 3000, "final": False},
-        )
-    finally:
-        app.dependency_overrides.clear()
+    sessions[(user.id, "paused1")] = s
+    resp = _client(db, user, override_dep).post(
+        f"/api/plex/item/{it.rating_key}/progress",
+        json={"position_seconds": 600, "duration_seconds": 3000, "final": False},
+    )
     assert resp.status_code == 200, resp.text
     assert stream.reap_idle() == 0, "the checkpoint did not say the viewer is still there"
-    assert "paused1" in sessions and not s.proc.killed
+    assert (user.id, "paused1") in sessions and not s.proc.killed
 
 
 def test_starting_a_session_leaves_another_viewers_paused_one_alone(
-    db, monkeypatch, tmp_path, sessions
+    db, monkeypatch, tmp_path, sessions, override_dep
 ):
     """The opportunistic sweep this route used to run was not scoped to the key being started: it
     walked the WHOLE registry with the 30 s finished rule, so pressing play on any item killed a
@@ -183,9 +182,9 @@ def test_starting_a_session_leaves_another_viewers_paused_one_alone(
     db.add(user)
     db.commit()
     paused = _Session(tmp_path, "paused", finished=True, idle_s=90)
-    sessions["someone-else"] = paused
+    sessions[(999, "someone-else")] = paused
 
-    def fake_start(db_, item, start, audio=None, aoff=0.0, multi=False, transcode=False):
+    def fake_start(db_, item, user_id, start, audio=None, aoff=0.0, multi=False, transcode=False):
         return SimpleNamespace(
             id="sid",
             media_start_s=start,
@@ -196,9 +195,6 @@ def test_starting_a_session_leaves_another_viewers_paused_one_alone(
         )
 
     monkeypatch.setattr(stream, "start_session", fake_start)
-    try:
-        resp = _client(db, user).post(f"/api/plex/stream/{started.rating_key}/session")
-    finally:
-        app.dependency_overrides.clear()
+    resp = _client(db, user, override_dep).post(f"/api/plex/stream/{started.rating_key}/session")
     assert resp.status_code == 200, resp.text
-    assert "someone-else" in sessions and not paused.proc.killed
+    assert (999, "someone-else") in sessions and not paused.proc.killed

backend/tests/test_http_details.py

@@ -0,0 +1,53 @@
+"""No refusal answers in a hand-written English sentence.
+
+The UI is bilingual and translates a structured `detail` (`{code, reason, …}`), but a string detail it
+can only print as it came — so ~150 of them reached the Hungarian UI verbatim, in the blocking error
+dialog and on every inline surface that shows `HttpError.detail`. `app/refusal.py` is the family they
+became; this test is what keeps a new one from being written the old way. Pure: it reads the sources.
+"""
+
+import ast
+import pathlib
+
+APP = pathlib.Path(__file__).resolve().parents[1] / "app"
+
+
+def _is_text(node: ast.AST) -> bool:
+    """A detail that is a sentence: a literal, an f-string, `str(exc)`, or `"…" + x`."""
+    if isinstance(node, ast.Constant) and isinstance(node.value, str):
+        return True
+    if isinstance(node, ast.JoinedStr):
+        return True
+    if isinstance(node, ast.Call) and getattr(node.func, "id", "") == "str":
+        return True
+    if isinstance(node, ast.BoolOp):
+        return any(_is_text(v) for v in node.values)
+    if isinstance(node, ast.BinOp):
+        return _is_text(node.left) or _is_text(node.right)
+    return False
+
+
+def test_no_http_exception_carries_a_sentence():
+    offenders = []
+    for path in sorted(APP.rglob("*.py")):
+        for node in ast.walk(ast.parse(path.read_text(encoding="utf-8"))):
+            if not (
+                isinstance(node, ast.Call)
+                and getattr(node.func, "id", getattr(node.func, "attr", "")) == "HTTPException"
+            ):
+                continue
+            kw = {k.arg: k.value for k in node.keywords}
+            detail = kw.get("detail", node.args[1] if len(node.args) > 1 else None)
+            if detail is not None and _is_text(detail):
+                offenders.append(f"{path.relative_to(APP).as_posix()}:{node.lineno}")
+    assert offenders == [], (
+        "a refusal with an English sentence for a detail — raise `refused(status, reason)` "
+        f"(app/refusal.py) and name the reason in both locales: {offenders}"
+    )
+
+
+def test_the_scan_sees_a_sentence_when_there_is_one():
+    """A guard that matches nothing is green over nothing."""
+    sample = ast.parse('HTTPException(status_code=400, detail=f"bad {x}")').body[0].value
+    assert _is_text(sample.keywords[1].value)
+    assert not _is_text(ast.parse('{"code": "refused", "reason": "x"}').body[0].value)

backend/tests/test_last_login.py

@@ -79,7 +79,7 @@ def test_the_demo_entry_does_not_stamp_the_shared_account(client, db):
 
     r = client.post("/auth/demo", json={"email": "visitor@example.com"})
 
-    assert r.json() == {"authenticated": True}
+    assert r.json() == {"ok": True, "authenticated": True}
     demo = auth_routes.get_or_create_demo_user(db)
     db.refresh(demo)
     assert demo.last_login_at is None
@@ -95,3 +95,13 @@ def test_the_admin_user_list_carries_last_login(as_user, db, make_user):
 
     assert rows["boss@example.com"]["last_login_at"].startswith("2026-09-16T08:30")
     assert rows[never.email]["last_login_at"] is None
+
+
+def test_the_account_sees_its_own_last_sign_in(client, db, make_user):
+    # Settings → Account shows it (prod UAT 2026-09-19: only the admin's user list did).
+    make_user(email="me@example.com", password=_PW)
+    client.post("/auth/password-login", json={"email": "me@example.com", "password": _PW})
+
+    stamp = client.get("/api/me").json()["last_login_at"]
+
+    assert _recent(datetime.fromisoformat(stamp))

backend/tests/test_like_literals.py

@@ -0,0 +1,81 @@
+"""What a person types is a literal inside a LIKE pattern, never a wildcard (DB-lane).
+
+`%` and `_` are LIKE wildcards. The feed's channel-name match and the live search's term fold both
+built their pattern from the typed text as it was, so `my_channel` also matched `myXchannel`, and a
+term already present as part of a longer word was never folded in.
+"""
+
+from datetime import datetime, timezone
+
+from sqlalchemy import select
+
+from app.models import Channel, Subscription, Video
+from app.routes.search import _fold_term
+
+
+def _video(vid: str, ch: str, title: str, search_terms: str | None = None) -> Video:
+    return Video(
+        id=vid,
+        channel_id=ch,
+        published_at=datetime(2024, 1, 1, tzinfo=timezone.utc),
+        title=title,
+        is_short=False,
+        live_status="none",
+        via_search=False,
+        via_explore=False,
+        search_terms=search_terms,
+    )
+
+
+def test_an_underscore_in_a_feed_search_matches_only_itself(db, as_user, make_user):
+    user = make_user()
+    db.add_all(
+        [
+            Channel(id="UCunder", title="build_log daily", subscriber_count=1),
+            Channel(id="UClookalike", title="buildXlog daily", subscriber_count=1),
+        ]
+    )
+    db.add_all(
+        [
+            Subscription(user_id=user.id, channel_id=ch, priority=0, hidden=False)
+            for ch in ("UCunder", "UClookalike")
+        ]
+    )
+    db.add_all(
+        [
+            _video("vidUnder", "UCunder", "Nothing in common"),
+            _video("vidLook", "UClookalike", "Nothing in common either"),
+        ]
+    )
+    db.commit()
+
+    resp = as_user(user).get("/api/feed?q=build_log&show=all&limit=50")
+
+    assert resp.status_code == 200, resp.text
+    assert {it["id"] for it in resp.json()["items"]} == {"vidUnder"}
+
+
+def test_a_term_is_folded_in_unless_it_is_already_a_whole_term(db):
+    db.add(Channel(id="UCfold", title="Fold", subscriber_count=1))
+    db.add_all(
+        [
+            _video("vidWord", "UCfold", "a", search_terms="category"),
+            _video("vidWild", "UCfold", "b", search_terms="catXdog"),
+            _video("vidHas", "UCfold", "c", search_terms="old cat_dog new"),
+            _video("vidNone", "UCfold", "d"),
+        ]
+    )
+    db.commit()
+
+    _fold_term(db, ["vidWord", "vidWild", "vidHas", "vidNone"], "cat")
+    _fold_term(db, ["vidWild", "vidHas"], "cat_dog")
+    db.commit()
+    db.expire_all()
+
+    terms = dict(db.execute(select(Video.id, Video.search_terms)).all())
+    assert terms == {
+        "vidWord": "category cat",
+        "vidWild": "catXdog cat cat_dog",
+        "vidHas": "old cat_dog new cat",
+        "vidNone": "cat",
+    }

backend/tests/test_log_pii.py

@@ -140,9 +140,9 @@ def test_a_refused_token_refresh_names_the_oauth_reason_and_not_its_prose(sink,
         request=httpx.Request("POST", "https://oauth2.googleapis.com/token"),
     )
     client = yt.YouTubeClient.__new__(yt.YouTubeClient)  # no HTTP client: `_send` is the stub
-    client.db = None
+    client.db = SimpleNamespace(add=lambda obj: None, commit=lambda: None)
     client.user = SimpleNamespace(
-        token=SimpleNamespace(access_token=None, expiry=None, refresh_token_enc=b"x")
+        id=1, token=SimpleNamespace(access_token=None, expiry=None, refresh_token_enc=b"x")
     )
     monkeypatch.setattr(yt, "decrypt_optional", lambda value: None)
     monkeypatch.setattr(yt, "decrypt", lambda value: "a-refresh-token")

backend/tests/test_logs.py

@@ -14,7 +14,7 @@ import logging
 from pathlib import Path
 
 import pytest
-from fastapi import FastAPI, Request
+from fastapi import FastAPI, HTTPException, Request
 from fastapi.testclient import TestClient
 
 from app import logs
@@ -213,6 +213,20 @@ def _client() -> TestClient:
     def _health():
         return {"ok": True}
 
+    @app.get("/api/admin/logs/facets")
+    def _log_console(fail: bool = False):
+        if fail:
+            raise HTTPException(status_code=400, detail={"code": "bad_cursor"})
+        return {"ok": True}
+
+    @app.get("/api/messages/unread_count")
+    def _unread():
+        return {"count": 0}
+
+    @app.post("/api/messages/unread_count")
+    def _unread_write():
+        return {"ok": True}
+
     @app.get("/boom")
     def _boom():
         raise RuntimeError("kaboom")
@@ -307,6 +321,43 @@ def test_the_healthcheck_is_logged_at_debug_so_it_cannot_drown_the_log(sink):
     assert len(sink.lines) == before
 
 
+def test_the_log_consoles_own_reads_are_debug_but_its_failures_are_not(sink):
+    http = logging.getLogger("siftlode.http")
+    http.setLevel(logs.TRACE)
+    client = _client()
+    client.get("/api/admin/logs/facets")
+    assert sink.objects()[-1]["level"] == "DEBUG"
+    client.get("/api/admin/logs/facets?fail=1")
+    assert sink.objects()[-1]["level"] == "WARNING"
+
+
+def test_a_polled_read_is_debug_a_write_to_the_same_route_is_not(sink):
+    # One open tab polled the unread counts, /api/me and the download index every 30 s: at INFO
+    # that was ~95% of the stored log on prod.
+    http = logging.getLogger("siftlode.http")
+    http.setLevel(logs.TRACE)
+    client = _client()
+    r = client.get("/api/messages/unread_count")
+    assert sink.objects()[-1]["level"] == "DEBUG"
+    # ...and says so, for the browser's copy of the line (frontend lib/http.ts).
+    assert r.headers["X-Log-Quiet"] == "1"
+    r = client.post("/api/messages/unread_count")
+    assert sink.objects()[-1]["level"] == "INFO"
+    assert "X-Log-Quiet" not in r.headers
+    client.get("/api/videos/abc")
+    assert sink.objects()[-1]["level"] == "INFO"
+
+
+def test_every_polled_route_is_a_route_the_app_has():
+    # The list names route TEMPLATES; one renamed on the router side would silently fall back to
+    # INFO, so the list is held to the app's own routes.
+    from app.main import app
+
+    # The schema, not `app.routes`: FastAPI 0.141 keeps an included router behind a wrapper there.
+    gets = {path for path, ops in app.openapi()["paths"].items() if "get" in ops}
+    assert logs._POLLED_ROUTES - gets == set()
+
+
 def test_a_failing_request_is_logged_by_status_and_an_unhandled_error_is_logged_at_all(sink):
     client = _client()
     client.get("/api/videos/missing/deeper")  # 404 from the router

backend/tests/test_override_dep_convention.py

@@ -0,0 +1,84 @@
+"""Dependency overrides go through `conftest.override_dep`, never `app.dependency_overrides` directly.
+
+The hand-rolled shape — assign, then `app.dependency_overrides.clear()` in a `finally` — wipes EVERY
+override, not the ones the test set, so it stops fixtures composing: one test's teardown silently
+clobbers an override another fixture installed. `override_dep` restores each key's prior value
+instead. 22 files had drifted to the hand-rolled shape (it was the house norm at ~20 files to 3), and
+the sweep that converted them is only as good as the check that keeps it converted — this one.
+"""
+
+from pathlib import Path
+
+TESTS = Path(__file__).parent
+
+
+def test_no_test_writes_dependency_overrides_directly():
+    offenders = [
+        f"{p.name}:{n}"
+        for p in sorted(TESTS.rglob("*.py"))
+        if p.name not in {"conftest.py", Path(__file__).name}
+        for n, line in enumerate(p.read_text(encoding="utf-8").splitlines(), 1)
+        if "dependency_overrides" in line
+    ]
+    assert offenders == [], "use the override_dep fixture: " + ", ".join(offenders)
+
+
+def test_a_request_gets_the_session_that_checks_its_commit():
+    """`get_db` is overridden with `db.info["request"]` — the test session plus the check that the
+    handler committed what it flushed (conftest `_request_dep`). A bare `lambda: db` hands the route
+    the same session without the check, and a handler that forgot its commit passes again."""
+    offenders = [
+        f"{p.name}:{n}"
+        for p in sorted(TESTS.rglob("*.py"))
+        if p.name != Path(__file__).name
+        for n, line in enumerate(p.read_text(encoding="utf-8").splitlines(), 1)
+        if "override_dep(get_db," in line and 'override_dep(get_db, db.info["request"])' not in line
+    ]
+    assert offenders == [], 'override get_db with db.info["request"]: ' + ", ".join(offenders)
+
+
+def test_the_commit_check_counts_only_the_root_transaction(db):
+    """A savepoint released inside a handler commits nothing to the database; ending it must not
+    clear the check (round 2). Driven directly, as a request would drive the dependency."""
+    import pytest
+    from starlette.requests import HTTPConnection
+
+    from app.models import User
+
+    conn = HTTPConnection(
+        {"type": "http", "method": "POST", "path": "/probe", "headers": [], "query_string": b""}
+    )
+    request = db.info["request"](conn)
+    session = next(request)
+    session.add(User(email="savepoint-probe@example.com"))
+    session.flush()
+    with session.begin_nested():
+        pass
+    with pytest.raises(StopIteration):
+        next(request)
+    assert db.info["unfinished"] == ["POST /probe"]
+    db.info["unfinished"].clear()  # recorded as it should be — not this test's failure
+
+
+def test_a_request_that_raises_leaves_nothing_it_did_not_commit(db):
+    """Production closes a failing request's session, which rolls back whatever it flushed and did
+    not commit; the shared test session must do the same, or a later read in the test sees a write
+    production would have lost (E16: the tracker's issue link, kept only by an explicit commit in
+    the handler's failure path). Driven directly, as a request would drive the dependency."""
+    import pytest
+    from sqlalchemy import select
+    from starlette.requests import HTTPConnection
+
+    from app.models import User
+
+    conn = HTTPConnection(
+        {"type": "http", "method": "POST", "path": "/probe", "headers": [], "query_string": b""}
+    )
+    request = db.info["request"](conn)
+    session = next(request)
+    session.add(User(email="rolled-back-probe@example.com"))
+    session.flush()
+    with pytest.raises(RuntimeError):
+        request.throw(RuntimeError("the handler failed"))
+    assert db.scalar(select(User).where(User.email == "rolled-back-probe@example.com")) is None
+    assert db.info["unfinished"] == []  # a failing request is rolled back, not reported

backend/tests/test_playlist_move.py

@@ -235,6 +235,13 @@ def test_item_edits_bump_updated_at(db, make_user, as_user):
     assert db.get(Playlist, src.id).updated_at > old
     assert db.get(Playlist, dst.id).updated_at > old
 
+    # …and removing one, the fourth item-only write (it had no test: E10 review coverage debt).
+    src.updated_at = old
+    db.commit()
+    assert client.delete(f"/api/playlists/{src.id}/items/v1").status_code == 200
+    db.expire_all()
+    assert db.get(Playlist, src.id).updated_at > old
+
 
 def test_the_list_endpoint_publishes_updated_at(db, make_user, as_user):
     user = make_user()
@@ -242,3 +249,49 @@ def test_the_list_endpoint_publishes_updated_at(db, make_user, as_user):
     rows = as_user(user).get("/api/playlists").json()
     assert len(rows) == 1
     assert rows[0]["updated_at"]  # the rail cannot sort by a field the API never sends
+
+
+def test_a_target_that_already_had_it_is_not_recently_changed(db, make_user, as_user):
+    """Moving into a list that already holds the video only removes it from the source: the
+    target did not change, and bumping it promoted an untouched list in the rail's sort."""
+    user = make_user()
+    _seed_videos(db, ["v1"])
+    src = _playlist(db, user, "Source", ["v1"])
+    dst = _playlist(db, user, "Target", ["v1"])
+    old = datetime.now(timezone.utc) - timedelta(days=3)
+    src.updated_at = old
+    dst.updated_at = old
+    db.commit()
+
+    assert _move(as_user(user), src.id, "v1", dst.id).status_code == 200
+    db.expire_all()
+    assert db.get(Playlist, src.id).updated_at > old
+    assert db.get(Playlist, dst.id).updated_at == old
+
+
+def test_a_concurrent_add_to_the_target_lands_as_the_already_present_move(
+    db, make_user, as_user, monkeypatch
+):
+    """The already-in-target check is a read, not a lock: another tab's add (or the scheduler's
+    YouTube merge) can commit the same video to the target in between, and the re-parent then
+    hits uq_playlist_video. That is the idempotent outcome arriving late — not a raw 500."""
+    from app.db import SessionLocal
+    from app.routes import playlists as plroutes
+
+    user = make_user()
+    _seed_videos(db, ["v1"])
+    src = _playlist(db, user, "Source", ["v1"])
+    dst = _playlist(db, user, "Target", [])
+    real = plroutes._next_item_position
+
+    def add_first(session, playlist_id):
+        with SessionLocal() as other:  # the other tab, committing between check and re-parent
+            other.add(PlaylistItem(playlist_id=dst.id, video_id="v1", position=0))
+            other.commit()
+        return real(session, playlist_id)
+
+    monkeypatch.setattr(plroutes, "_next_item_position", add_first)
+    assert _move(as_user(user), src.id, "v1", dst.id).status_code == 200
+    db.expire_all()
+    assert _ids(db, src.id) == []
+    assert _ids(db, dst.id) == ["v1"]

backend/tests/test_plex_clear_resume_push.py

@@ -42,7 +42,7 @@ def _seed(db, *, status: str, position: int):
     return it, user
 
 
-def _clear(db, user, it, monkeypatch) -> list[tuple]:
+def _clear(db, user, it, monkeypatch, override_dep) -> list[tuple]:
     """Drive the endpoint with the Plex link satisfied and the background push recorded."""
     pushes: list[tuple] = []
     monkeypatch.setattr(state, "_configured_cache", True)  # pass the instance-setup request gate
@@ -52,32 +52,29 @@ def _clear(db, user, it, monkeypatch) -> list[tuple]:
         "push_state_to_plex",
         lambda user_id, item_id, rating_key, action, *rest: pushes.append((rating_key, action)),
     )
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        resp = TestClient(app).post(f"/api/plex/item/{it.rating_key}/state", json={"status": "new"})
-        assert resp.status_code == 200, resp.text
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    resp = TestClient(app).post(f"/api/plex/item/{it.rating_key}/state", json={"status": "new"})
+    assert resp.status_code == 200, resp.text
     return pushes
 
 
-def test_clearing_an_in_progress_item_tells_plex(db, monkeypatch):
+def test_clearing_an_in_progress_item_tells_plex(db, monkeypatch, override_dep):
     # The regression: status "new" + a position IS the in-progress shape, and it must push.
     it, user = _seed(db, status="new", position=92)
-    assert _clear(db, user, it, monkeypatch) == [("98614", "unwatched")]
+    assert _clear(db, user, it, monkeypatch, override_dep) == [("98614", "unwatched")]
     assert db.query(PlexState).count() == 0
 
 
-def test_clearing_a_watched_item_still_tells_plex(db, monkeypatch):
+def test_clearing_a_watched_item_still_tells_plex(db, monkeypatch, override_dep):
     # The case the old guard did cover — kept, so the fix cannot narrow into a new hole.
     it, user = _seed(db, status="watched", position=0)
-    assert _clear(db, user, it, monkeypatch) == [("98614", "unwatched")]
+    assert _clear(db, user, it, monkeypatch, override_dep) == [("98614", "unwatched")]
 
 
-def test_unhiding_touches_plex_not_at_all(db, monkeypatch):
+def test_unhiding_touches_plex_not_at_all(db, monkeypatch, override_dep):
     # `hidden` is a Siftlode-only concept "with no Plex analogue, so it never touches Plex" — the
     # endpoint's own docstring. The old status-only guard pushed here anyway, un-marking an item on
     # Plex that the user had merely hidden.
     it, user = _seed(db, status="hidden", position=0)
-    assert _clear(db, user, it, monkeypatch) == []
+    assert _clear(db, user, it, monkeypatch, override_dep) == []

backend/tests/test_plex_collection_sort.py

@@ -231,61 +231,70 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _order(r) -> list[str]:
     return [i["title"] for i in r.json()["items"]]
 
 
-def test_collection_detail_defaults_to_release_year_ascending(db, monkeypatch):
+def test_collection_detail_defaults_to_release_year_ascending(db, monkeypatch, override_dep):
     """The order the page had before it grew a control — a franchise reads in release order."""
     user = _seed(db)
-    r = _get(db, user, monkeypatch, "/api/plex/collections/col1")
+    r = _get(db, user, monkeypatch, override_dep, "/api/plex/collections/col1")
     assert r.status_code == 200
     assert _order(r) == ["Zulu", "Mike", "Series", "Alpha"]
 
 
-def test_collection_detail_honours_sort_and_direction(db, monkeypatch):
+def test_collection_detail_honours_sort_and_direction(db, monkeypatch, override_dep):
     user = _seed(db)
-    r = _get(db, user, monkeypatch, "/api/plex/collections/col1?sort=year&sort_dir=desc")
+    r = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/collections/col1?sort=year&sort_dir=desc"
+    )
     assert _order(r) == ["Alpha", "Series", "Mike", "Zulu"]
-    r = _get(db, user, monkeypatch, "/api/plex/collections/col1?sort=title&sort_dir=asc")
+    r = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/collections/col1?sort=title&sort_dir=asc"
+    )
     assert _order(r) == ["Alpha", "Mike", "Series", "Zulu"]
-    r = _get(db, user, monkeypatch, "/api/plex/collections/col1?sort=rating&sort_dir=desc")
+    r = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/collections/col1?sort=rating&sort_dir=desc"
+    )
     # The show has no rating, so it sinks — it is not "rated 0".
     assert _order(r) == ["Zulu", "Mike", "Alpha", "Series"]
 
 
-def test_lastwatched_ranks_a_shows_episodes_alongside_the_movies(db, monkeypatch):
+def test_lastwatched_ranks_a_shows_episodes_alongside_the_movies(db, monkeypatch, override_dep):
     """The show leg needs the rollup's `resumed_at`; with only a status map this key would order
     every show as never-watched."""
     user = _seed(db)
-    r = _get(db, user, monkeypatch, "/api/plex/collections/col1?sort=lastwatched&sort_dir=desc")
+    r = _get(
+        db,
+        user,
+        monkeypatch,
+        override_dep,
+        "/api/plex/collections/col1?sort=lastwatched&sort_dir=desc",
+    )
     # Series (episode resumed NOW) > Zulu (watched 2 days ago) > the two never-touched, title-asc.
     assert _order(r) == ["Series", "Zulu", "Alpha", "Mike"]
 
 
-def test_collections_list_resolves_titles_by_key(db, monkeypatch):
+def test_collections_list_resolves_titles_by_key(db, monkeypatch, override_dep):
     """What a shared Plex link needs: the URL carries bare rating_keys, so the sidebar token and the
     filter chip have nothing to show but `17045` until these are resolved."""
     user = _seed(db)
-    r = _get(db, user, monkeypatch, "/api/plex/collections?keys=col1")
+    r = _get(db, user, monkeypatch, override_dep, "/api/plex/collections?keys=col1")
     assert r.status_code == 200
     assert [c["title"] for c in r.json()["collections"]] == ["Franchise"]
 
 
-def test_an_empty_keys_param_asks_for_nothing(db, monkeypatch):
+def test_an_empty_keys_param_asks_for_nothing(db, monkeypatch, override_dep):
     """`keys=` with nothing in it must not fall through to "every collection" — that would be a
     200 KB answer to a question about zero ids."""
     user = _seed(db)
-    r = _get(db, user, monkeypatch, "/api/plex/collections?keys=")
+    r = _get(db, user, monkeypatch, override_dep, "/api/plex/collections?keys=")
     assert r.status_code == 200
     assert r.json()["collections"] == []

backend/tests/test_plex_collections_filter.py

@@ -58,44 +58,44 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _titles(resp):
     return {i["title"] for i in resp.json()["items"]}
 
 
-def test_single_collection_filters_to_its_members(db, monkeypatch):
+def test_single_collection_filters_to_its_members(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&collections=A")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&collections=A")
     assert _titles(resp) == {"Only A", "A and B"}
 
 
-def test_multiple_collections_any_is_the_union(db, monkeypatch):
+def test_multiple_collections_any_is_the_union(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&collections=A,B")
+    resp = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&collections=A,B"
+    )
     assert _titles(resp) == {"Only A", "Only B", "A and B"}
 
 
-def test_multiple_collections_all_is_the_intersection(db, monkeypatch):
+def test_multiple_collections_all_is_the_intersection(db, monkeypatch, override_dep):
     user = _seed(db)
     resp = _get(
         db,
         user,
         monkeypatch,
+        override_dep,
         "/api/plex/library?scope=movie&collections=A,B&collection_mode=all",
     )
     assert _titles(resp) == {"A and B"}
 
 
-def test_collection_cards_carry_montage_art_and_total_runtime(db, monkeypatch):
+def test_collection_cards_carry_montage_art_and_total_runtime(db, monkeypatch, override_dep):
     # The browse-tile montage (top films, best-rated first) + the collection's total runtime.
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
@@ -127,14 +127,16 @@ def test_collection_cards_carry_montage_art_and_total_runtime(db, monkeypatch):
     db.commit()
     card = next(
         c
-        for c in _get(db, user, monkeypatch, "/api/plex/collections").json()["collections"]
+        for c in _get(db, user, monkeypatch, override_dep, "/api/plex/collections").json()[
+            "collections"
+        ]
         if c["id"] == "A"
     )
     assert card["art"] == ["m2", "m1"]  # best-rated first (m2 9.0 > m1 8.0)
     assert card["total_runtime_s"] == 5400  # 3600 + 1800
 
 
-def test_create_collection_rejects_duplicate_name(db, monkeypatch):
+def test_create_collection_rejects_duplicate_name(db, monkeypatch, override_dep):
     # Same-named collections conflate in Plex, so a create with an existing name (case-insensitive) is
     # rejected 409 — BEFORE any Plex call (the guard runs first, so the DB lane can assert it).
     monkeypatch.setattr(state, "_configured_cache", True)
@@ -146,21 +148,18 @@ def test_create_collection_rejects_duplicate_name(db, monkeypatch):
     user = User(email="dup@example.com")
     db.add(user)
     db.commit()
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    app.dependency_overrides[admin_user] = lambda: user
-    try:
-        r = TestClient(app).post(
-            "/api/plex/collections",
-            json={"library": "1", "title": "marvel", "item_rating_key": "m1"},
-        )
-        assert r.status_code == 409, r.text
-        assert r.json()["detail"] == {"code": "collection", "reason": "name_taken"}
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    override_dep(admin_user, lambda: user)
+    r = TestClient(app).post(
+        "/api/plex/collections",
+        json={"library": "1", "title": "marvel", "item_rating_key": "m1"},
+    )
+    assert r.status_code == 409, r.text
+    assert r.json()["detail"] == {"code": "collection", "reason": "name_taken"}
 
 
-def test_collection_detail_hero_and_ordered_members(db, monkeypatch):
+def test_collection_detail_hero_and_ordered_members(db, monkeypatch, override_dep):
     # The Collection info page: hero aggregates (year range, most-restrictive cert, total runtime) +
     # members ordered by release year then title.
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
@@ -195,7 +194,7 @@ def test_collection_detail_hero_and_ordered_members(db, monkeypatch):
     user = User(email="cd@example.com")
     db.add(user)
     db.commit()
-    d = _get(db, user, monkeypatch, "/api/plex/collections/A").json()
+    d = _get(db, user, monkeypatch, override_dep, "/api/plex/collections/A").json()
     assert d["title"] == "Coll A" and d["summary"] == "S"
     assert d["year_min"] == 1992 and d["year_max"] == 1996
     assert d["content_rating"] == "PG"  # most restrictive of {G, PG}
@@ -270,38 +269,32 @@ def _seed_editable(db):
     return lib, user
 
 
-def _admin_client(db, user, monkeypatch, stub, resync=_resync_ok):
+def _admin_client(db, user, monkeypatch, override_dep, stub, resync=_resync_ok):
     monkeypatch.setattr(state, "_configured_cache", True)
     monkeypatch.setattr(coll_routes, "PlexClient", lambda db: stub)
     monkeypatch.setattr(coll_routes.plex_sync, "resync_collection", resync)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    app.dependency_overrides[admin_user] = lambda: user
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    override_dep(admin_user, lambda: user)
     return TestClient(app)
 
 
-def test_rename_writes_through_to_plex(db, monkeypatch):
+def test_rename_writes_through_to_plex(db, monkeypatch, override_dep):
     _lib, user = _seed_editable(db)
     stub = _CollStub()
-    client = _admin_client(db, user, monkeypatch, stub)
-    try:
-        r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
-        assert r.status_code == 200, r.text
-        assert "rename_collection" in stub.calls
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub)
+    r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
+    assert r.status_code == 200, r.text
+    assert "rename_collection" in stub.calls
 
 
-def test_remove_item_writes_through_to_plex(db, monkeypatch):
+def test_remove_item_writes_through_to_plex(db, monkeypatch, override_dep):
     _lib, user = _seed_editable(db)
     stub = _CollStub()
-    client = _admin_client(db, user, monkeypatch, stub)
-    try:
-        r = client.delete("/api/plex/collections/A/items/m1")
-        assert r.status_code == 200, r.text
-        assert "remove_collection_item" in stub.calls
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub)
+    r = client.delete("/api/plex/collections/A/items/m1")
+    assert r.status_code == 200, r.text
+    assert "remove_collection_item" in stub.calls
 
 
 def _resync_create(db, plex, lib, rk):
@@ -312,25 +305,22 @@ def _resync_create(db, plex, lib, rk):
     return col
 
 
-def test_create_writes_through_to_plex(db, monkeypatch):
+def test_create_writes_through_to_plex(db, monkeypatch, override_dep):
     _lib, user = _seed_editable(db)
     stub = _CollStub()
-    client = _admin_client(db, user, monkeypatch, stub, resync=_resync_create)
-    try:
-        r = client.post(
-            "/api/plex/collections",
-            json={"library": "1", "title": "Fresh Coll", "item_rating_key": "m1"},
-        )
-        assert r.status_code == 200, r.text
-        assert "create_collection" in stub.calls
-        body = r.json()
-        assert body["id"] == "NEW"  # the stub's new ratingKey
-        assert body["editable"] is True  # create marks the new collection editable
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub, resync=_resync_create)
+    r = client.post(
+        "/api/plex/collections",
+        json={"library": "1", "title": "Fresh Coll", "item_rating_key": "m1"},
+    )
+    assert r.status_code == 200, r.text
+    assert "create_collection" in stub.calls
+    body = r.json()
+    assert body["id"] == "NEW"  # the stub's new ratingKey
+    assert body["editable"] is True  # create marks the new collection editable
 
 
-def test_create_resync_failure_is_422(db, monkeypatch):
+def test_create_resync_failure_is_422(db, monkeypatch, override_dep):
     # The collection was created in Plex (wrote=True) but the follow-up resync read failed → 422 with
     # the honest "reconcile on the next sync" detail, not a false "write failed".
     _lib, user = _seed_editable(db)
@@ -339,34 +329,28 @@ def test_create_resync_failure_is_422(db, monkeypatch):
     def _boom(db_, plex, lib_, rk):
         raise PlexError("read failed")
 
-    client = _admin_client(db, user, monkeypatch, stub, resync=_boom)
-    try:
-        r = client.post(
-            "/api/plex/collections",
-            json={"library": "1", "title": "Fresh Coll", "item_rating_key": "m1"},
-        )
-        assert r.status_code == 422, r.text
-        assert "reconcile" in r.json()["detail"].lower()
-        assert "create_collection" in stub.calls
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub, resync=_boom)
+    r = client.post(
+        "/api/plex/collections",
+        json={"library": "1", "title": "Fresh Coll", "item_rating_key": "m1"},
+    )
+    assert r.status_code == 422, r.text
+    assert r.json()["detail"] == {"code": "refused", "reason": "collection_pending_sync"}
+    assert "create_collection" in stub.calls
 
 
-def test_mutation_failure_returns_422_write_failed(db, monkeypatch):
+def test_mutation_failure_returns_422_write_failed(db, monkeypatch, override_dep):
     # The Plex mutation itself raised → the write never landed → 422 "Plex write failed", and resync
     # is never reached (stub.calls holds only the mutating call).
     _lib, user = _seed_editable(db)
     stub = _CollStub(fail_on="rename_collection")
-    client = _admin_client(db, user, monkeypatch, stub)
-    try:
-        r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
-        assert r.status_code == 422, r.text
-        assert "write failed" in r.json()["detail"].lower()
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub)
+    r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
+    assert r.status_code == 422, r.text
+    assert r.json()["detail"] == {"code": "refused", "reason": "plex_write_failed"}
 
 
-def test_resync_failure_after_successful_write_is_422_and_rolls_back(db, monkeypatch):
+def test_resync_failure_after_successful_write_is_422_and_rolls_back(db, monkeypatch, override_dep):
     # The mutation landed on Plex; only the follow-up refresh READ failed. We must (a) NOT claim a
     # write failure and NOT use a 5xx (which the frontend treats as offline) → 422 with a "reconcile
     # on the next sync" detail, and (b) roll back any partial local upsert the resync had flushed.
@@ -385,21 +369,18 @@ def test_resync_failure_after_successful_write_is_422_and_rolls_back(db, monkeyp
         db_.flush()
         raise PlexError("read failed")
 
-    client = _admin_client(db, user, monkeypatch, stub, resync=_resync_boom)
-    try:
-        r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
-        assert r.status_code == 422, r.text
-        assert "reconcile" in r.json()["detail"].lower()
-        assert "rename_collection" in stub.calls  # the write DID happen
-    finally:
-        app.dependency_overrides.clear()
+    client = _admin_client(db, user, monkeypatch, override_dep, stub, resync=_resync_boom)
+    r = client.patch("/api/plex/collections/A", json={"title": "Renamed"})
+    assert r.status_code == 422, r.text
+    assert r.json()["detail"] == {"code": "refused", "reason": "collection_pending_sync"}
+    assert "rename_collection" in stub.calls  # the write DID happen
     row = (
         db.execute(select(PlexCollection).where(PlexCollection.rating_key == "A")).scalars().first()
     )
     assert row.title == "My Coll"  # the partial resync upsert was rolled back
 
 
-def test_show_collection_gets_montage_art_from_shows(db, monkeypatch):
+def test_show_collection_gets_montage_art_from_shows(db, monkeypatch, override_dep):
     # A show-library collection must get its montage from PlexShow members (else it renders blank) — the
     # A3 fix that unions movie + show art. Runtime stays 0 (shows have no single duration).
     lib = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
@@ -431,7 +412,9 @@ def test_show_collection_gets_montage_art_from_shows(db, monkeypatch):
     db.commit()
     card = next(
         c
-        for c in _get(db, user, monkeypatch, "/api/plex/collections").json()["collections"]
+        for c in _get(db, user, monkeypatch, override_dep, "/api/plex/collections").json()[
+            "collections"
+        ]
         if c["id"] == "S"
     )
     assert card["art"] == ["s2", "s1"]  # show members, best-rated first

backend/tests/test_plex_detail.py

@@ -191,14 +191,11 @@ def test_enrich_people_batch_persists_detail(db):
 # ---- item_detail serving (DB lane) ---------------------------------------------------------------
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)  # pass the request gate
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _user(db, email):
@@ -208,7 +205,7 @@ def _user(db, email):
     return u
 
 
-def test_item_detail_movie_serves_from_row_despite_live_outage(db, monkeypatch):
+def test_item_detail_movie_serves_from_row_despite_live_outage(db, monkeypatch, override_dep):
     """An enriched movie serves cast/IMDb/tagline from the DB row even when the live Plex call raises —
     only markers/streams (which need the live meta) degrade."""
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
@@ -237,7 +234,7 @@ def test_item_detail_movie_serves_from_row_despite_live_outage(db, monkeypatch):
     db.commit()
 
     monkeypatch.setattr(detail_routes, "PlexClient", lambda db: _StubClient(raise_=True))
-    resp = _get(db, user, monkeypatch, "/api/plex/item/m1")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/item/m1")
     assert resp.status_code == 200, resp.text
     body = resp.json()
     assert body["imdb_rating"] == 8.7
@@ -249,7 +246,7 @@ def test_item_detail_movie_serves_from_row_despite_live_outage(db, monkeypatch):
     assert body["markers"] == []  # live fetch failed → markers degrade, but detail survived
 
 
-def test_item_detail_movie_lazy_fills_when_unenriched(db, monkeypatch):
+def test_item_detail_movie_lazy_fills_when_unenriched(db, monkeypatch, override_dep):
     """A not-yet-enriched movie is filled from the live meta on view (and persisted for next time)."""
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
@@ -261,7 +258,7 @@ def test_item_detail_movie_lazy_fills_when_unenriched(db, monkeypatch):
     db.commit()
 
     monkeypatch.setattr(detail_routes, "PlexClient", lambda db: _StubClient(RICH_META))
-    resp = _get(db, user, monkeypatch, "/api/plex/item/m1")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/item/m1")
     assert resp.status_code == 200, resp.text
     assert resp.json()["imdb_id"] == "tt0068646"
     db.refresh(mv)
@@ -270,7 +267,7 @@ def test_item_detail_movie_lazy_fills_when_unenriched(db, monkeypatch):
     assert [c["name"] for c in mv.full_cast] == ["Marlon Brando", "Al Pacino"]
 
 
-def test_item_detail_episode_serves_rich_from_live(db, monkeypatch):
+def test_item_detail_episode_serves_rich_from_live(db, monkeypatch, override_dep):
     """Episodes are never enriched (not in the grid, no HU overlay), so their detail is parsed from the
     live meta the endpoint fetches for markers/streams."""
     lib = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
@@ -288,7 +285,7 @@ def test_item_detail_episode_serves_rich_from_live(db, monkeypatch):
     db.commit()
 
     monkeypatch.setattr(detail_routes, "PlexClient", lambda db: _StubClient(RICH_META))
-    resp = _get(db, user, monkeypatch, "/api/plex/item/e1")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/item/e1")
     assert resp.status_code == 200, resp.text
     body = resp.json()
     assert body["imdb_id"] == "tt0068646"  # from the live meta, not the (NULL) row
@@ -297,7 +294,7 @@ def test_item_detail_episode_serves_rich_from_live(db, monkeypatch):
     assert ep.full_cast is None  # episodes are not persisted/enriched
 
 
-def test_show_detail_serves_from_row(db, monkeypatch):
+def test_show_detail_serves_from_row(db, monkeypatch, override_dep):
     """A show serves cast/IMDb from the DB row; `related` failing (Plex down) must not drop the detail."""
     lib = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
     db.add(lib)
@@ -324,7 +321,7 @@ def test_show_detail_serves_from_row(db, monkeypatch):
         raise RuntimeError("plex unavailable")
 
     monkeypatch.setattr(detail_routes, "_show_enrichment", _boom)
-    resp = _get(db, user, monkeypatch, "/api/plex/show/s1")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/show/s1")
     assert resp.status_code == 200, resp.text
     body = resp.json()["show"]
     assert body["imdb_rating"] == 9.1
@@ -334,7 +331,7 @@ def test_show_detail_serves_from_row(db, monkeypatch):
     assert resp.json()["related"] == []
 
 
-def test_show_detail_lazy_fills_when_unenriched(db, monkeypatch):
+def test_show_detail_lazy_fills_when_unenriched(db, monkeypatch, override_dep):
     """A not-yet-enriched show is filled from the live meta on first view (imdb/full_cast persisted +
     stamped) so subsequent views serve from the row."""
     lib = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
@@ -348,7 +345,7 @@ def test_show_detail_lazy_fills_when_unenriched(db, monkeypatch):
 
     # _show_enrichment returns (live meta, no related) → the fill branch runs.
     monkeypatch.setattr(detail_routes, "_show_enrichment", lambda db_, rk: (RICH_META, []))
-    resp = _get(db, user, monkeypatch, "/api/plex/show/s1")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/show/s1")
     assert resp.status_code == 200, resp.text
     assert resp.json()["show"]["imdb_id"] == "tt0068646"
     db.refresh(show)

backend/tests/test_plex_discover.py

@@ -120,24 +120,21 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        client = TestClient(app)  # no context manager: skip lifespan
-        return client.get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    client = TestClient(app)  # no context manager: skip lifespan
+    return client.get(path)
 
 
 def _ids(cards):
     return [c["id"] for c in cards]
 
 
-def test_discover_shape_and_recently_added_order(db, monkeypatch):
+def test_discover_shape_and_recently_added_order(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/discover?scope=both")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both")
     assert resp.status_code == 200, resp.text
     d = resp.json()
     assert set(d) >= {"continue_watching", "recently_added", "genres", "because_you_watched"}
@@ -148,19 +145,19 @@ def test_discover_shape_and_recently_added_order(db, monkeypatch):
     assert genres.get("Drama") == 2 and genres.get("Comedy") == 1
 
 
-def test_genre_tiles_carry_poster_art(db, monkeypatch):
+def test_genre_tiles_carry_poster_art(db, monkeypatch, override_dep):
     # Each genre tile carries up to 4 poster rating_keys for the 2×2 collage (top_art_keys): the top
     # movies in that genre, best-rated then newest. No ratings here → newest-first; shows are excluded.
     user = _seed(db)
-    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=both").json()
+    d = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both").json()
     art = {g["value"]: g["art"] for g in d["genres"]}
     assert art["Drama"] == ["m1", "m3"]  # both Drama movies, m1 (newer) first
     assert art["Comedy"] == ["m2"]
 
 
-def test_continue_watching_movies_and_shows(db, monkeypatch):
+def test_continue_watching_movies_and_shows(db, monkeypatch, override_dep):
     user = _seed(db)
-    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=both").json()
+    d = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both").json()
     ids = _ids(d["continue_watching"])
     # The in-progress movie and the show with an in-progress episode are both present; the watched
     # anchor movie (m1) is not. Order is most-recently-progressed first (the show's ep beats m3).
@@ -168,7 +165,7 @@ def test_continue_watching_movies_and_shows(db, monkeypatch):
     assert "m1" not in ids
 
 
-def test_continue_watching_null_status_in_hidden_out(db, monkeypatch):
+def test_continue_watching_null_status_in_hidden_out(db, monkeypatch, override_dep):
     # A started movie whose PlexState.status is NULL is still "in progress": `NULL NOT IN (...)` is NULL
     # (not TRUE), so a bare notin_ would wrongly drop it — the or_(is_(None), notin_) branch keeps it.
     # A hidden started movie must be excluded.
@@ -207,13 +204,15 @@ def test_continue_watching_null_status_in_hidden_out(db, monkeypatch):
     db.commit()
 
     ids = _ids(
-        _get(db, user, monkeypatch, "/api/plex/discover?scope=movie").json()["continue_watching"]
+        _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=movie").json()[
+            "continue_watching"
+        ]
     )
     assert "mn" in ids  # NULL-status started movie IS in progress
     assert "mh" not in ids  # hidden is excluded
 
 
-def test_continue_watching_excludes_fully_watched_show(db, monkeypatch):
+def test_continue_watching_excludes_fully_watched_show(db, monkeypatch, override_dep):
     # A show whose every episode is watched is DONE, not in-progress: the `watched < total` guard must
     # keep it off the Continue-watching rail (a bare `watched > 0` would wrongly resurface it).
     lib_s = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
@@ -248,14 +247,16 @@ def test_continue_watching_excludes_fully_watched_show(db, monkeypatch):
     db.commit()
 
     ids = _ids(
-        _get(db, user, monkeypatch, "/api/plex/discover?scope=show").json()["continue_watching"]
+        _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=show").json()[
+            "continue_watching"
+        ]
     )
     assert "shw" not in ids  # fully watched → excluded from continue-watching
 
 
-def test_because_you_watched_resolves_in_library_recs(db, monkeypatch):
+def test_because_you_watched_resolves_in_library_recs(db, monkeypatch, override_dep):
     user = _seed(db)
-    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=both").json()
+    d = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both").json()
     bw = d["because_you_watched"]
     assert bw is not None
     assert bw["anchor"]["id"] == "m1" and bw["anchor"]["title"] == "Anchor Movie"
@@ -263,34 +264,36 @@ def test_because_you_watched_resolves_in_library_recs(db, monkeypatch):
     assert _ids(bw["items"]) == ["m2"]
 
 
-def test_because_you_watched_null_without_history(db, monkeypatch):
+def test_because_you_watched_null_without_history(db, monkeypatch, override_dep):
     _seed(db)
     fresh = User(email="fresh-discover@example.com")
     db.add(fresh)
     db.commit()
-    d = _get(db, fresh, monkeypatch, "/api/plex/discover?scope=both").json()
+    d = _get(db, fresh, monkeypatch, override_dep, "/api/plex/discover?scope=both").json()
     # A user with no watched-and-enriched movie gets no recommendation rail.
     assert d["because_you_watched"] is None
     assert d["continue_watching"] == []
 
 
-def test_surprise_scope_and_bound(db, monkeypatch):
+def test_surprise_scope_and_bound(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/surprise?scope=movie&limit=2")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/surprise?scope=movie&limit=2")
     assert resp.status_code == 200, resp.text
     items = resp.json()["items"]
     assert len(items) <= 2
     assert all(c["type"] == "movie" for c in items)  # scope=movie excludes shows
 
 
-def test_recently_watched_movies_and_episodes(db, monkeypatch):
+def test_recently_watched_movies_and_episodes(db, monkeypatch, override_dep):
     # The rail lists last-fully-watched titles newest-first: a watched MOVIE as its own card, a show as
     # the specific watched EPISODE (with its show title). _seed watches m1 (movie); add a watched episode.
     user = _seed(db)
     ep2 = db.execute(select(PlexItem).where(PlexItem.rating_key == "sh1e2")).scalars().one()
     db.add(PlexState(user_id=user.id, item_id=ep2.id, status="watched", watched_at=NOW))
     db.commit()
-    rw = _get(db, user, monkeypatch, "/api/plex/discover?scope=both").json()["recently_watched"]
+    rw = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both").json()[
+        "recently_watched"
+    ]
     by_id = {c["id"]: c for c in rw}
     assert "m1" in by_id and by_id["m1"]["type"] == "movie"
     assert "sh1e2" in by_id and by_id["sh1e2"]["type"] == "episode"
@@ -299,11 +302,13 @@ def test_recently_watched_movies_and_episodes(db, monkeypatch):
     assert set(_ids(rw)) == {"m1", "sh1e2"}
 
 
-def test_surprise_excludes_watched_and_caps_per_kind(db, monkeypatch):
+def test_surprise_excludes_watched_and_caps_per_kind(db, monkeypatch, override_dep):
     # Surprise surfaces only UNSEEN titles: the watched movie (m1) is out; the unwatched (m2), the
     # in-progress movie (m3) and the partially-watched show (sh1) are eligible. Capped at 3 per kind.
     user = _seed(db)
-    items = _get(db, user, monkeypatch, "/api/plex/surprise?scope=both").json()["items"]
+    items = _get(db, user, monkeypatch, override_dep, "/api/plex/surprise?scope=both").json()[
+        "items"
+    ]
     ids = _ids(items)
     assert "m1" not in ids  # watched → excluded
     assert set(ids) <= {"m2", "m3", "sh1"}  # only unseen titles
@@ -311,19 +316,21 @@ def test_surprise_excludes_watched_and_caps_per_kind(db, monkeypatch):
     assert len([c for c in items if c["type"] == "show"]) <= 3
 
 
-def test_discover_scope_movie_excludes_shows(db, monkeypatch):
+def test_discover_scope_movie_excludes_shows(db, monkeypatch, override_dep):
     user = _seed(db)
-    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=movie").json()
+    d = _get(db, user, monkeypatch, override_dep, "/api/plex/discover?scope=movie").json()
     assert all(c["type"] == "movie" for c in d["recently_added"])
     # The show drops out of continue watching under the movie scope.
     assert _ids(d["continue_watching"]) == ["m3"]
 
 
-def test_filters_narrow_every_discover_rail(db, monkeypatch):
+def test_filters_narrow_every_discover_rail(db, monkeypatch, override_dep):
     # The sidebar filters constrain the Discover rails just like the Browse grid (ask 3). A genre=Drama
     # filter keeps only the Drama titles across every rail; the genre-less show and the Comedy rec drop.
     user = _seed(db)
-    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=both&genres=Drama").json()
+    d = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/discover?scope=both&genres=Drama"
+    ).json()
     # Recently-added: m1 + m3 (Drama) survive; Comedy m2 and the genre-less show sh1 are filtered out.
     assert set(_ids(d["recently_added"])) == {"m1", "m3"}
     # Continue-watching: only the in-progress Drama movie remains (the show has no genres → excluded).
@@ -334,10 +341,10 @@ def test_filters_narrow_every_discover_rail(db, monkeypatch):
     assert d["because_you_watched"] is None
 
 
-def test_filters_narrow_surprise(db, monkeypatch):
+def test_filters_narrow_surprise(db, monkeypatch, override_dep):
     user = _seed(db)
-    items = _get(db, user, monkeypatch, "/api/plex/surprise?scope=movie&genres=Comedy").json()[
-        "items"
-    ]
+    items = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/surprise?scope=movie&genres=Comedy"
+    ).json()["items"]
     # Only the one Comedy movie qualifies under the filter.
     assert _ids(items) == ["m2"]

backend/tests/test_plex_facets.py

@@ -16,7 +16,7 @@ from app.main import app
 from app.models import PlexItem, PlexLibrary, PlexShow, User
 
 
-def test_facets_returns_studio_vocabulary(db, monkeypatch):
+def test_facets_returns_studio_vocabulary(db, monkeypatch, override_dep):
     """E5 S7: /facets returns the studio vocabulary (distinct studio + count) for the sidebar picker."""
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
@@ -33,18 +33,15 @@ def test_facets_returns_studio_vocabulary(db, monkeypatch):
     db.add(user)
     db.commit()
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        resp = TestClient(app).get("/api/plex/facets?scope=movie")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    resp = TestClient(app).get("/api/plex/facets?scope=movie")
     assert resp.status_code == 200, resp.text
     studios = {s["value"]: s["count"] for s in resp.json()["studios"]}
     assert studios == {"Pixar": 2, "A24": 1}
 
 
-def test_facets_survives_json_null_genres(db, monkeypatch):
+def test_facets_survives_json_null_genres(db, monkeypatch, override_dep):
     lib = PlexLibrary(plex_key="1", title="Shows", kind="show", enabled=True)
     db.add(lib)
     db.flush()
@@ -61,13 +58,10 @@ def test_facets_survives_json_null_genres(db, monkeypatch):
     db.execute(text("UPDATE plex_shows SET genres = 'null'::jsonb WHERE rating_key = 's1'"))
     db.commit()
 
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        client = TestClient(app)  # no context-manager: skip lifespan (scheduler/HLS sweep)
-        resp = client.get("/api/plex/facets?scope=show")
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    client = TestClient(app)  # no context-manager: skip lifespan (scheduler/HLS sweep)
+    resp = client.get("/api/plex/facets?scope=show")
 
     assert resp.status_code == 200, resp.text
     # The scalar-null show contributes no genres — and, crucially, doesn't abort the whole endpoint.

backend/tests/test_plex_field_scoped_search.py

@@ -100,14 +100,11 @@ def _seed(db):
     return {"user": user}
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _ids(body):
@@ -115,55 +112,75 @@ def _ids(body):
 
 
 class TestFieldScopedSearch:
-    def test_everywhere_matches_every_facet(self, db, monkeypatch):
+    def test_everywhere_matches_every_facet(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=all").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=all"
+        ).json()
         # title (mt), cast (mp), summary (ms) all land in the item grid; the episode is grouped out
         assert _ids(body) == ["mp", "ms", "mt"]
         assert [e["title"] for e in body["episodes"]] == ["Zephyr Episode"]
 
-    def test_field_all_is_identical_to_default(self, db, monkeypatch):
+    def test_field_all_is_identical_to_default(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        default = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr").json()
-        scoped = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=all").json()
+        default = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr"
+        ).json()
+        scoped = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=all"
+        ).json()
         assert _ids(default) == _ids(scoped) == ["mp", "ms", "mt"]
         assert default["total"] == scoped["total"]
         assert [e["id"] for e in default["episodes"]] == [e["id"] for e in scoped["episodes"]]
 
-    def test_title_scope_narrows_to_title_match(self, db, monkeypatch):
+    def test_title_scope_narrows_to_title_match(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=title").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=title"
+        ).json()
         assert _ids(body) == ["mt"]
         assert body["total"] == 1
         assert body["episodes"] == []  # non-episode field scopes suppress the episode section
 
-    def test_people_scope_narrows_to_cast_match(self, db, monkeypatch):
+    def test_people_scope_narrows_to_cast_match(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=people").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=people"
+        ).json()
         assert _ids(body) == ["mp"]
 
-    def test_summary_scope_narrows_to_description_match(self, db, monkeypatch):
+    def test_summary_scope_narrows_to_description_match(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=summary").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=summary"
+        ).json()
         assert _ids(body) == ["ms"]
 
-    def test_episode_scope_empties_grid_and_returns_episode(self, db, monkeypatch):
+    def test_episode_scope_empties_grid_and_returns_episode(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=episode").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=episode"
+        ).json()
         assert body["items"] == []
         assert body["total"] == 0
         assert [e["title"] for e in body["episodes"]] == ["Zephyr Episode"]
 
-    def test_episode_scope_needs_shows_in_scope(self, db, monkeypatch):
+    def test_episode_scope_needs_shows_in_scope(self, db, monkeypatch, override_dep):
         s = _seed(db)
         body = _get(
-            db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=episode&scope=movie"
+            db,
+            s["user"],
+            monkeypatch,
+            override_dep,
+            "/api/plex/library?q=zephyr&field=episode&scope=movie",
         ).json()
         # movie-only scope has no show libraries -> no episodes to surface, and the grid stays empty
         assert body["items"] == []
         assert body["episodes"] == []
 
-    def test_unknown_field_falls_back_to_everywhere(self, db, monkeypatch):
+    def test_unknown_field_falls_back_to_everywhere(self, db, monkeypatch, override_dep):
         s = _seed(db)
-        body = _get(db, s["user"], monkeypatch, "/api/plex/library?q=zephyr&field=bogus").json()
+        body = _get(
+            db, s["user"], monkeypatch, override_dep, "/api/plex/library?q=zephyr&field=bogus"
+        ).json()
         assert _ids(body) == ["mp", "ms", "mt"]

backend/tests/test_plex_finish.py

@@ -0,0 +1,80 @@
+"""The near-end checkpoint that finishes a Plex item.
+
+- Exactly one scrobble per finish, even when two near-end checkpoints race (the 10 s tick and the
+  debounced `seeked` flush arrive together): the transition is decided by a conditional write, not a
+  read taken before it.
+- The finish supersedes every resume push still in flight, so none can land at Plex after the
+  scrobble and revive a resume point on a watched item.
+"""
+
+import threading
+from datetime import datetime, timedelta, timezone
+
+from sqlalchemy import select
+
+from app.db import SessionLocal
+from app.models import PlexItem, PlexLibrary, PlexState
+from app.routes.plex import playback
+
+
+def _item(db) -> PlexItem:
+    lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
+    db.add(lib)
+    db.flush()
+    item = PlexItem(rating_key="m1", library_id=lib.id, kind="movie", title="A Movie")
+    db.add(item)
+    db.commit()
+    return item
+
+
+def test_two_racing_finishes_flip_the_row_once(db, make_user):
+    user = make_user()
+    item = _item(db)
+    db.add(PlexState(user_id=user.id, item_id=item.id, status="new", position_seconds=5000))
+    db.commit()
+    now = datetime.now(timezone.utc)
+
+    first, second = SessionLocal(), SessionLocal()
+    try:
+        assert playback._mark_finished(first, user.id, item.id, now) is True  # holds the row lock
+        out: list[bool] = []
+        racer = threading.Thread(
+            target=lambda: out.append(playback._mark_finished(second, user.id, item.id, now))
+        )
+        racer.start()
+        racer.join(0.5)
+        assert racer.is_alive(), "the second writer must wait on the first one's row lock"
+        first.commit()
+        racer.join(5)
+        second.commit()
+    finally:
+        first.close()
+        second.close()
+    assert out == [False], "the second checkpoint saw the committed finish: no second scrobble"
+
+
+def test_a_first_ever_finish_inserts_and_counts_once(db, make_user):
+    user = make_user()
+    item = _item(db)
+    now = datetime.now(timezone.utc)
+    assert playback._mark_finished(db, user.id, item.id, now) is True
+    db.commit()
+    assert playback._mark_finished(db, user.id, item.id, now + timedelta(seconds=10)) is False
+    db.commit()
+    st = db.execute(select(PlexState).where(PlexState.item_id == item.id)).scalars().one()
+    assert (st.status, st.position_seconds) == ("watched", 0)
+
+
+def test_the_finish_supersedes_a_resume_push_still_in_flight(db, as_user, make_user, monkeypatch):
+    user = make_user()
+    item = _item(db)
+    monkeypatch.setattr(playback.plex_stream, "touch_session", lambda uid, key: None)
+    earlier = datetime.now(timezone.utc) - timedelta(seconds=5)
+    # A resume push was scheduled a moment ago and has not reached Plex yet.
+    assert playback._should_push_resume(user.id, item.id, earlier, final=True)
+
+    r = as_user(user).post(
+        "/api/plex/item/m1/progress", json={"position_seconds": 2995, "duration_seconds": 3000}
+    )
+    assert r.json() == {"ok": True, "status": "watched", "position_seconds": 0}
+    assert playback._resume_push_superseded(user.id, item.id, earlier) is True

backend/tests/test_plex_hls_file_route.py

@@ -38,6 +38,9 @@ class _Proc:
         return 0
 
 
+VIEWER = 41  # the id of the account the test client is signed in as
+
+
 class _Session:
     def __init__(self, session_id: str, directory, running: bool = False, audio_langs=None):
         self.id = session_id
@@ -59,14 +62,11 @@ def sessions(monkeypatch):
 
 
 @pytest.fixture
-def client(monkeypatch):
+def client(monkeypatch, override_dep):
     monkeypatch.setattr(state, "_configured_cache", True)
-    user = User(email="hls@example.com")
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        yield TestClient(app)
-    finally:
-        app.dependency_overrides.pop(current_user, None)
+    user = User(id=VIEWER, email="hls@example.com")
+    override_dep(current_user, lambda: user)
+    return TestClient(app)
 
 
 def test_a_segment_is_served_from_the_session_the_url_names(client, tmp_path, sessions):
@@ -74,12 +74,23 @@ def test_a_segment_is_served_from_the_session_the_url_names(client, tmp_path, se
     d.mkdir()
     (d / "seg_11.ts").write_bytes(b"")  # its predecessor, so seg_12 is the next one
     (d / "seg_12.ts").write_bytes(b"mine")
-    sessions["m1"] = _Session("sid-a", d)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d)
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_12.ts")
     assert r.status_code == 200, r.text
     assert r.content == b"mine"
 
 
+def test_another_viewers_session_of_the_same_item_is_not_this_viewers(client, tmp_path, sessions):
+    """Sessions are per viewer: a second account playing the same film has its own, and knowing its
+    id does not make it yours — resolution is by (viewer, item) before the id is compared."""
+    d = tmp_path / "m1_u7_0_0_+0.00"
+    d.mkdir()
+    (d / "index.m3u8").write_bytes(b"#EXTM3U")
+    sessions[(7, "m1")] = _Session("sid-a", d)
+    r = client.get("/api/plex/stream/m1/hls/sid-a/index.m3u8")
+    assert r.status_code == 404, r.text
+
+
 def test_a_segment_of_a_replaced_session_is_a_404_not_the_new_sessions_bytes(
     client, tmp_path, sessions
 ):
@@ -89,7 +100,7 @@ def test_a_segment_of_a_replaced_session_is_a_404_not_the_new_sessions_bytes(
     theirs.mkdir()
     (theirs / "seg_11.ts").write_bytes(b"")
     (theirs / "seg_12.ts").write_bytes(b"theirs")
-    sessions["m1"] = _Session("sid-b", theirs)
+    sessions[(VIEWER, "m1")] = _Session("sid-b", theirs)
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_12.ts")
     assert r.status_code == 404, r.text
     assert b"theirs" not in r.content
@@ -105,7 +116,7 @@ def test_a_playlist_with_no_live_session_is_a_404_not_a_silent_restart_at_zero(
     monkeypatch.setattr(
         plex_stream,
         "start_session",
-        lambda *a, **k: started.append(a[2] if len(a) > 2 else 0.0),
+        lambda *a, **k: started.append(a[3] if len(a) > 3 else 0.0),
     )
     r = client.get("/api/plex/stream/m1/hls/sid-gone/index.m3u8")
     assert r.status_code == 404, r.text
@@ -122,7 +133,7 @@ def test_a_segment_that_will_never_arrive_fails_at_once(client, tmp_path, sessio
     d = tmp_path / "m1_0_0_+0.00"
     d.mkdir()
     (d / "seg_0.ts").write_bytes(b"x")  # the session is producing; seg_99999 is simply not next
-    sessions["m1"] = _Session("sid-a", d, running=True)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=True)
     started = time.monotonic()
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_99999.ts")
     elapsed = time.monotonic() - started
@@ -150,7 +161,7 @@ def test_a_multi_audio_segment_beyond_the_region_fails_at_once_too(
     d.mkdir()
     (d / "seg_0_0.ts").write_bytes(b"x")
     (d / "seg_a0_0.ts").write_bytes(b"x")
-    sessions["m1"] = _Session("sid-a", d, running=True, audio_langs=["hu", "en"])
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=True, audio_langs=["hu", "en"])
     started = time.monotonic()
     r = client.get(f"/api/plex/stream/m1/hls/sid-a/{name}")
     elapsed = time.monotonic() - started
@@ -166,7 +177,7 @@ def test_a_multi_audio_segment_whose_predecessor_exists_is_served(client, tmp_pa
     d.mkdir()
     (d / "seg_a0_0.ts").write_bytes(b"x")
     (d / "seg_a0_1.ts").write_bytes(b"audio")
-    sessions["m1"] = _Session("sid-a", d, running=True, audio_langs=["hu", "en"])
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=True, audio_langs=["hu", "en"])
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_a0_1.ts")
     assert r.status_code == 200, r.text
     assert r.content == b"audio"
@@ -179,7 +190,7 @@ def test_a_name_the_session_cannot_produce_fails_at_once(client, tmp_path, sessi
     its playlists and its segments and nothing else, so any other name is answerable now."""
     d = tmp_path / "m1_0_0_+0.00"
     d.mkdir()
-    sessions["m1"] = _Session("sid-a", d, running=True)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=True)
     started = time.monotonic()
     r = client.get("/api/plex/stream/m1/hls/sid-a/nope.m3u8")
     elapsed = time.monotonic() - started
@@ -194,7 +205,7 @@ def test_an_absurd_segment_index_is_a_404_not_a_500(client, tmp_path, sessions,
     subtitle routes were bounded for; the answer is the same 404 any other unproducible name gets."""
     d = tmp_path / "m1_0_0_+0.00"
     d.mkdir()
-    sessions["m1"] = _Session("sid-a", d, running=True)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=True)
     r = client.get(f"/api/plex/stream/m1/hls/sid-a/seg_{'9' * digits}.ts")
     assert r.status_code == 404, r.text
 
@@ -209,7 +220,7 @@ def test_a_session_torn_down_during_the_read_is_a_404_not_a_500(
     d = tmp_path / "m1_0_0_+0.00"
     d.mkdir()
     (d / "seg_11.ts").write_bytes(b"")
-    sessions["m1"] = _Session("sid-a", d)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d)
     # The file existed when the wait checked, and is gone by the time the route reads it.
     monkeypatch.setattr(plex_stream, "wait_for", lambda *a, **k: True)
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_12.ts")
@@ -224,7 +235,7 @@ def test_a_dead_producer_is_not_waited_out(client, tmp_path, sessions):
     d = tmp_path / "m1_0_0_+0.00"
     d.mkdir()
     (d / "seg_5.ts").write_bytes(b"x")
-    sessions["m1"] = _Session("sid-a", d, running=False)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", d, running=False)
     started = time.monotonic()
     r = client.get("/api/plex/stream/m1/hls/sid-a/seg_6.ts")
     elapsed = time.monotonic() - started
@@ -294,10 +305,10 @@ def test_a_name_only_the_other_argv_branch_writes_is_refused_at_once(tmp_path, c
     30.0 s and `seg_a0_0.ts` 20.1 s to answer 404 (deep-review round 7)."""
     single = tmp_path / "m1_0_0_+0.00"
     single.mkdir()
-    sessions["m1"] = _Session("sid-a", single, running=True)
+    sessions[(VIEWER, "m1")] = _Session("sid-a", single, running=True)
     multi = tmp_path / "m2_0_multi_+0.00"
     multi.mkdir()
-    sessions["m2"] = _Session("sid-b", multi, running=True, audio_langs=["hu", "en"])
+    sessions[(VIEWER, "m2")] = _Session("sid-b", multi, running=True, audio_langs=["hu", "en"])
 
     # Each of these belongs to the other shape (or to no shape at all) and must be refused without
     # a wait — the assertion is the ELAPSED time as much as the status.
@@ -315,8 +326,8 @@ def test_a_name_only_the_other_argv_branch_writes_is_refused_at_once(tmp_path, c
             )
 
     # And the control: the names each session CAN write are still waited for, not refused.
-    assert plex_stream.artifact_may_arrive(sessions["m1"], "index.m3u8")
-    assert plex_stream.artifact_may_arrive(sessions["m1"], "seg_0.ts")
-    assert plex_stream.artifact_may_arrive(sessions["m2"], "master.m3u8")
-    assert plex_stream.artifact_may_arrive(sessions["m2"], "stream_a1.m3u8")
-    assert plex_stream.artifact_may_arrive(sessions["m2"], "seg_a1_0.ts")
+    assert plex_stream.artifact_may_arrive(sessions[(VIEWER, "m1")], "index.m3u8")
+    assert plex_stream.artifact_may_arrive(sessions[(VIEWER, "m1")], "seg_0.ts")
+    assert plex_stream.artifact_may_arrive(sessions[(VIEWER, "m2")], "master.m3u8")
+    assert plex_stream.artifact_may_arrive(sessions[(VIEWER, "m2")], "stream_a1.m3u8")
+    assert plex_stream.artifact_may_arrive(sessions[(VIEWER, "m2")], "seg_a1_0.ts")

backend/tests/test_plex_keyword_filter.py

@@ -41,34 +41,33 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _titles(resp):
     return {i["title"] for i in resp.json()["items"]}
 
 
-def test_keyword_filter_narrows_to_matching_rows(db, monkeypatch):
+def test_keyword_filter_narrows_to_matching_rows(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&keywords=heist")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&keywords=heist")
     assert resp.status_code == 200, resp.text
     assert _titles(resp) == {"Heist Movie"}
 
 
-def test_no_keyword_filter_returns_all(db, monkeypatch):
+def test_no_keyword_filter_returns_all(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie")
     assert _titles(resp) == {"Heist Movie", "Space Movie", "No Keywords Movie"}
 
 
-def test_unknown_keyword_matches_nothing(db, monkeypatch):
+def test_unknown_keyword_matches_nothing(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&keywords=nonesuch")
+    resp = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&keywords=nonesuch"
+    )
     assert resp.json()["items"] == []

backend/tests/test_plex_lang.py

@@ -56,54 +56,55 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(
         state, "_configured_cache", True
     )  # the request gate 503s an unconfigured app
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        client = TestClient(app)  # no context manager: skip lifespan
-        return client.get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    client = TestClient(app)  # no context manager: skip lifespan
+    return client.get(path)
 
 
 def _titles(resp):
     return {i["title"] for i in resp.json()["items"]}
 
 
-def test_library_serves_active_language_titles(db, monkeypatch):
+def test_library_serves_active_language_titles(db, monkeypatch, override_dep):
     user = _seed(db)
-    hu = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&lang=hu")
-    en = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&lang=en")
+    hu = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&lang=hu")
+    en = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&lang=en")
     # HU serves the twin's Hungarian title; the EN-only row falls back to its English title.
     assert _titles(hu) == {"Magyar Cím", "EN Only"}
     assert _titles(en) == {"English Title", "EN Only"}
 
 
-def test_facets_vocabulary_is_language_specific(db, monkeypatch):
+def test_facets_vocabulary_is_language_specific(db, monkeypatch, override_dep):
     user = _seed(db)
-    hu = _get(db, user, monkeypatch, "/api/plex/facets?scope=movie&lang=hu")
-    en = _get(db, user, monkeypatch, "/api/plex/facets?scope=movie&lang=en")
+    hu = _get(db, user, monkeypatch, override_dep, "/api/plex/facets?scope=movie&lang=hu")
+    en = _get(db, user, monkeypatch, override_dep, "/api/plex/facets?scope=movie&lang=en")
     hu_genres = {g["value"] for g in hu.json()["genres"]}
     en_genres = {g["value"] for g in en.json()["genres"]}
     assert "Dráma" in hu_genres and "Drama" not in hu_genres
     assert "Drama" in en_genres and "Dráma" not in en_genres
 
 
-def test_genre_filter_matches_active_language_vocabulary(db, monkeypatch):
+def test_genre_filter_matches_active_language_vocabulary(db, monkeypatch, override_dep):
     user = _seed(db)
     # The HU genre chip filters the HU column; the same string against the EN column matches nothing.
-    hit = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&lang=hu&genres=Dráma")
-    miss = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&lang=en&genres=Dráma")
+    hit = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&lang=hu&genres=Dráma"
+    )
+    miss = _get(
+        db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&lang=en&genres=Dráma"
+    )
     assert _titles(hit) == {"Magyar Cím"}
     assert miss.json()["items"] == []
 
 
-def test_item_detail_language_and_rating_split(db, monkeypatch):
+def test_item_detail_language_and_rating_split(db, monkeypatch, override_dep):
     user = _seed(db)
-    resp = _get(db, user, monkeypatch, "/api/plex/item/m1?lang=hu")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/item/m1?lang=hu")
     body = resp.json()
     assert body["title"] == "Magyar Cím"
     assert body["summary"] == "Magyar összefoglaló."
@@ -112,15 +113,15 @@ def test_item_detail_language_and_rating_split(db, monkeypatch):
     assert body["rating"] == 6.5
 
 
-def test_hu_search_still_finds_en_only_titles(db, monkeypatch):
+def test_hu_search_still_finds_en_only_titles(db, monkeypatch, override_dep):
     user = _seed(db)
     # m2 ("EN Only") has no HU twin, so search_vector_hu carries no title tokens for it. HU-mode search
     # must still match it via the EN vector (vector_match's union) — findable by its English title.
-    resp = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&lang=hu&q=Only")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&lang=hu&q=Only")
     assert "EN Only" in _titles(resp)
 
 
-def test_rating_filter_prefers_imdb_over_audience(db, monkeypatch):
+def test_rating_filter_prefers_imdb_over_audience(db, monkeypatch, override_dep):
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
     db.flush()
@@ -142,7 +143,7 @@ def test_rating_filter_prefers_imdb_over_audience(db, monkeypatch):
     user = User(email="rating@example.com")
     db.add(user)
     db.commit()
-    hit = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&rating_min=7")
+    hit = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&rating_min=7")
     assert "High IMDb" in _titles(hit)
-    miss = _get(db, user, monkeypatch, "/api/plex/library?scope=movie&rating_min=9")
+    miss = _get(db, user, monkeypatch, override_dep, "/api/plex/library?scope=movie&rating_min=9")
     assert "High IMDb" not in _titles(miss)

backend/tests/test_plex_last_watched_sort.py

@@ -111,44 +111,53 @@ def _seed(db):
     return user
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
 def _ids(resp):
     return [i["id"] for i in resp.json()["items"]]
 
 
-def test_movies_ordered_by_last_watched_desc(db, monkeypatch):
+def test_movies_ordered_by_last_watched_desc(db, monkeypatch, override_dep):
     user = _seed(db)
     resp = _get(
-        db, user, monkeypatch, "/api/plex/library?scope=movie&sort=lastwatched&sort_dir=desc"
+        db,
+        user,
+        monkeypatch,
+        override_dep,
+        "/api/plex/library?scope=movie&sort=lastwatched&sort_dir=desc",
     )
     assert resp.status_code == 200, resp.text
     # Newest resume, then the watched-only (coalesce → watched_at), then the older resume, then never.
     assert _ids(resp) == ["mo_new", "mo_watched", "mo_old", "mo_never"]
 
 
-def test_shows_ordered_by_last_watched_desc(db, monkeypatch):
+def test_shows_ordered_by_last_watched_desc(db, monkeypatch, override_dep):
     user = _seed(db)
     resp = _get(
-        db, user, monkeypatch, "/api/plex/library?scope=show&sort=lastwatched&sort_dir=desc"
+        db,
+        user,
+        monkeypatch,
+        override_dep,
+        "/api/plex/library?scope=show&sort=lastwatched&sort_dir=desc",
     )
     assert resp.status_code == 200, resp.text
     # Recent resume first, then the watched-only show, then the never-watched one (nullslast).
     assert _ids(resp) == ["sh_recent", "sh_watched", "sh_never"]
 
 
-def test_last_watched_mixed_scope_nullslast(db, monkeypatch):
+def test_last_watched_mixed_scope_nullslast(db, monkeypatch, override_dep):
     user = _seed(db)
     resp = _get(
-        db, user, monkeypatch, "/api/plex/library?scope=both&sort=lastwatched&sort_dir=desc"
+        db,
+        user,
+        monkeypatch,
+        override_dep,
+        "/api/plex/library?scope=both&sort=lastwatched&sort_dir=desc",
     )
     assert resp.status_code == 200, resp.text
     ids = _ids(resp)

backend/tests/test_plex_person.py

@@ -25,17 +25,14 @@ from app.plex.query import content_libs
 NAME = "Robert De Niro"
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)  # pass the request gate
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)  # no lifespan (skip scheduler/HLS sweep)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)  # no lifespan (skip scheduler/HLS sweep)
 
 
-def test_person_detail_returns_cast_and_director_credits(db, monkeypatch):
+def test_person_detail_returns_cast_and_director_credits(db, monkeypatch, override_dep):
     movies_lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     shows_lib = PlexLibrary(plex_key="2", title="Shows", kind="show", enabled=True)
     off_lib = PlexLibrary(plex_key="3", title="Off", kind="movie", enabled=False)
@@ -89,7 +86,7 @@ def test_person_detail_returns_cast_and_director_credits(db, monkeypatch):
     db.add(PlexState(user_id=user.id, item_id=heat.id, status="watched"))
     db.commit()
 
-    resp = _get(db, user, monkeypatch, f"/api/plex/person/{NAME.replace(' ', '%20')}")
+    resp = _get(db, user, monkeypatch, override_dep, f"/api/plex/person/{NAME.replace(' ', '%20')}")
     assert resp.status_code == 200, resp.text
     body = resp.json()
 
@@ -106,7 +103,7 @@ def test_person_detail_returns_cast_and_director_credits(db, monkeypatch):
     assert body["shows"][0]["type"] == "show"
 
 
-def test_person_detail_unknown_name_is_empty(db, monkeypatch):
+def test_person_detail_unknown_name_is_empty(db, monkeypatch, override_dep):
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
     db.flush()
@@ -123,7 +120,7 @@ def test_person_detail_unknown_name_is_empty(db, monkeypatch):
     db.add(user)
     db.commit()
 
-    resp = _get(db, user, monkeypatch, "/api/plex/person/Ghost%20Actor")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/person/Ghost%20Actor")
     assert resp.status_code == 200, resp.text
     body = resp.json()
     # An unknown name has no plex_people row → no bio, no titles (E5 S6 added the bio fields, all null).

backend/tests/test_plex_person_bio.py

@@ -168,17 +168,14 @@ def test_enrich_person_noop_without_tmdb_id(db, monkeypatch):
     assert plex_tmdb.enrich_person(db, person) is False
 
 
-def _get(db, user, monkeypatch, path):
+def _get(db, user, monkeypatch, override_dep, path):
     monkeypatch.setattr(state, "_configured_cache", True)
-    app.dependency_overrides[get_db] = lambda: db
-    app.dependency_overrides[current_user] = lambda: user
-    try:
-        return TestClient(app).get(path)
-    finally:
-        app.dependency_overrides.clear()
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: user)
+    return TestClient(app).get(path)
 
 
-def test_person_detail_schedules_enrich_off_request_path(db, monkeypatch):
+def test_person_detail_schedules_enrich_off_request_path(db, monkeypatch, override_dep):
     # The bio fetch runs OFF the request path (a background task after the response), so the serve never
     # makes a live TMDB call. An un-enriched person (tmdb_person_id set + tmdb_enriched_at None) schedules
     # the enrich and the page still renders immediately with whatever's in the row (bio still null).
@@ -196,7 +193,7 @@ def test_person_detail_schedules_enrich_off_request_path(db, monkeypatch):
     monkeypatch.setattr(people, "_enrich_person_bg", lambda pid: scheduled.append(pid))
     people._enrich_inflight.clear()  # ensure the per-person cooldown guard doesn't suppress this open
 
-    resp = _get(db, user, monkeypatch, "/api/plex/person/Lazy P")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/person/Lazy P")
     assert resp.status_code == 200, resp.text
     assert resp.json()["biography"] is None  # not enriched yet — the bio lands by the next open
     assert len(scheduled) == 1  # the enrich was scheduled off the request path
@@ -260,7 +257,7 @@ def test_should_schedule_enrich_dedups_within_cooldown():
     people._enrich_inflight.clear()
 
 
-def test_person_detail_no_enrich_when_already_enriched(db, monkeypatch):
+def test_person_detail_no_enrich_when_already_enriched(db, monkeypatch, override_dep):
     # An already-enriched person (tmdb_enriched_at set) must NOT schedule another background fetch.
     from datetime import datetime, timezone
 
@@ -284,13 +281,13 @@ def test_person_detail_no_enrich_when_already_enriched(db, monkeypatch):
     scheduled: list[int] = []
     monkeypatch.setattr(people, "_enrich_person_bg", lambda pid: scheduled.append(pid))
 
-    resp = _get(db, user, monkeypatch, "/api/plex/person/Done P")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/person/Done P")
     assert resp.status_code == 200, resp.text
     assert resp.json()["biography"] == "Bio."
     assert scheduled == []  # already enriched → no background work
 
 
-def test_person_detail_serves_bio_and_resolves_known_for(db, monkeypatch):
+def test_person_detail_serves_bio_and_resolves_known_for(db, monkeypatch, override_dep):
     lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
     db.add(lib)
     db.flush()
@@ -327,7 +324,7 @@ def test_person_detail_serves_bio_and_resolves_known_for(db, monkeypatch):
     db.add(user)
     db.commit()
 
-    resp = _get(db, user, monkeypatch, "/api/plex/person/Actor X")
+    resp = _get(db, user, monkeypatch, override_dep, "/api/plex/person/Actor X")
     assert resp.status_code == 200, resp.text
     j = resp.json()
     assert j["biography"] == "Bio here."