The explore purge rebuilt followed_channel's two EXISTS clauses inline, so what is polled and what may be deleted could drift; it now uses the predicate, which moved to sync/explore.py. The env validator and sysconfig each folded a choice value on their own; both call config.canonical_choice. The deep-backfill comment no longer calls recent backfill unconditional.
The log now has a stored, queryable copy for the diagnostics console:
every WARNING and above plus the request line of every request, kept
for log_retention_days (default 7, no "forever") and pruned hourly by
the new log_gc job.
Rows are built on the logging thread from the same redacted fields as
the stdout line, queued without blocking and written in batches by one
background thread on its own connection. A full queue or a failed write
drops and reports instead of retrying. Flood control keeps 30 of any
one message per minute plus a count of the rest; anonymous request
lines are capped at 60 a minute per client, and the client address is
never stored. Deleting an account deletes its stored events.
Measured on prod first: a YouTube RSS outage wrote 11k warnings in four
hours, one per channel per poll. The poll now writes one warning with
per-reason counts and a few examples, and a failure on our side gets
one traceback per poll instead of one per channel.
log_level, search_source, download_layout and the transcode hw/preset
were typed by hand, and every consumer carried its own guess at what a
typo meant. The value set is now a Literal in config.py: pydantic
rejects a bad env value at boot (any letter case accepted), sysconfig
refuses a bad override and derives the admin picker's options from the
same Literal, and the consumers read the value as-is.
The Configuration page renders a choice key as a segmented bar, or a
dropdown past six options, with translated option names. Its tabs now
follow the registry's order instead of a hand-kept copy that had
already dropped the explore group.
A single-choice FilterSelect now opens on the option in use: in the
browser it could land on the first row instead.
A deployment printed four different log formats and none of them could be
joined up: uvicorn's log_config.json for the API, a hand-rolled StreamHandler in
main.py for anything not started by uvicorn, logging.basicConfig() in the worker
and in the download child (no timestamp at all), and alembic's fileConfig.
app/logs.py replaces all four with one JSON line per event (OpenTelemetry's log
data model, no SDK): ts, level, severity, source, logger, event code, message,
attributes, plus the correlation the context carries — request id, account,
download job.
Redaction is applied at the HANDLER, not at the call sites: every message, every
attribute and every traceback is scrubbed on the way out, so a secret cannot
leak by being forgotten at one of ~125 call sites. Passwords, tokens, cookies,
secret config values and email addresses never reach a line.
The access log is ours now (`http.request`): the route template instead of the
concrete path, the status, the duration and the account — and never the query
string, which uvicorn's access log printed on every single request (`?account=`,
`?source=`, the `?token=` of a share link). A well-formed client request id is
accepted and echoed in X-Request-Id, so a browser line and a server line join up.
The account comes from `request.state`, filled by the auth dependency: the
middleware is the outermost one, so it runs outside SessionMiddleware and in a
different task context.
`log_level` becomes an admin knob (sysconfig), applied without a restart and
re-applied at startup — best-effort on purpose, since a logging knob must never
be what stops the app from booting. Every compose service gets bounded json-file
logs (3×50 MB): Docker keeps every line forever by default, and the API now
writes one line per request.
Verified on the localdev stack: JSON everywhere including alembic and the
worker, the query strings gone, a supplied X-Request-Id echoed and logged, and
three /healthz hits of which only the one made while the level was DEBUG
produced a line.
Bug hunt 2026-09, item 14 — "how does the multichannel downmix work, and is it
normalised?" It isn't: `plex/stream.py` has always encoded `-c:a aac -ac 2 -b:a
192k`, i.e. fixed stereo with ffmpeg's default downmix matrix and no loudness
handling at all, which is why a film mastered for a cinema arrives with whispered
dialogue and deafening action.
New admin knob `plex_audio_loudnorm` (Configuration → Plex), DEFAULT OFF: it makes
a film markedly louder and narrows its dynamic range, which is a taste call rather
than a fix. It sits at the end of the Plex group, after the software-transcode
knobs — it is an audio concern, not one of the libx264 ones.
-af aformat=channel_layouts=stereo,loudnorm=I=-16:TP=-1.5:LRA=11,aresample=48000
Three things about that chain are load-bearing and each has a test:
* the downmix is FORCED FIRST rather than left to `-ac 2` — measuring 5.1 and
folding it down afterwards would normalise something other than what is heard;
* the trailing resample is not decoration: `loudnorm` runs its own resampler at
192 kHz internally, which the AAC encoder will not take;
* one `-af`, no stream index, so EVERY audio rendition of a multi-audio file is
normalised — not just the first.
The knob is also part of the session directory name (`…_multi-ln_+0.00`), because
it changes the audio the segments contain, and a session left over from before the
admin flipped it must not be mistaken for one that honours it. The suffix is
appended 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 what may be a
shared scratch path. A test pins both halves — the name changes, and the sweep
still recognises it.
Measured end-to-end on the app's own HLS segments (a real 5.1 AC3 file, same item,
same 160 s offset, same ten segments): OFF -35.2 LUFS, ON -17.2 LUFS. On a 60 s
bench: I -27.6 → -16.6 LUFS with LRA 13.3 → 9.8 LU. A/V sync is untouched — under
this pipeline's own `-copyts` the audio start PTS is identical with and without the
filter, so the 3 s lookahead desyncs nothing.
Direct-played files are served untouched and stay so; a 5.1 mix is always `remux`,
so the reported case is fully covered.
The software-fallback re-encode now runs deprioritized and admin-configurable.
The SW transcode ffmpeg child is niced (preexec_fn → os.nice, applied per-child
because the Popen lives in the long-lived API process, which must NOT itself be
niced — unlike the download worker's whole-process _deprioritize) so a CPU-bound
re-encode can't starve request handling or playback; the VAAPI path needs none of
it.
New sysconfig knobs (plex group, rendered on the admin Configuration page, i18n
HU/EN): plex_transcode_hw (auto/on/off, layered onto _want_hw), plex_transcode_
preset, plex_transcode_crf, plex_transcode_max_height (software-only downscale-to
cap; the GPU path encodes at source resolution). plex_max_transcodes stays the
concurrency cap (comment corrected — the fallback is shipped, not "later").
pytest extends the command-builder + _want_hw coverage (preset/crf/max_height
plumbing, the on/off/auto policy). Browser-UAT'd: max_height=240 drops the live
resolution to 330x240; the SW ffmpeg child runs at nice 10 (ppid=api process).
Deep-review remediation for the E7 upload path, all findings adversarially verified:
- Serve every library file with a Content-Type chosen from the ffprobe-verified media_kind
+ a strict container allow-list (storage.served_media_type), never guessed from the
user-controlled file extension. Closes a stored-XSS vector where a media/HTML polyglot
uploaded as "evil.html" was served inline as text/html on the login-free /watch surface.
Applied to both the authenticated /file and the public watch_file endpoints.
- Classify uploaded still images (jpg/png/gif/webp/…) as media_kind='file' so they are
force-downloaded and don't get a broken in-app video player.
- Roll back the on-disk side of an upload when the ingest transaction fails after place_file
(unlink the placed file + its deterministic poster path), so a failed commit can't orphan
bytes in the GC-skipped .uploads tree.
- Floor download_upload_max_bytes at min=1 so a stored 0 can't silently disable the per-file cap.
- Dedupe the ffprobe-JSON invocation into edit.run_ffprobe_json (shared by probe_codecs and
upload._probe) and the upload extension into storage._clean_upload_ext; drop the now-unused
parse_probe_streams.
Tests: public + authenticated force-download and the polyglot-not-served-as-HTML guard, the
real _probe classifier (image/cover-art/dims/duration), the ingest rollback/cleanup path, the
max_jobs branch, the cap-floor invariant, and run_ffprobe_json error handling.
Add the non-yt-dlp ingest path so a user-uploaded file joins the same download
library and inherits its function set. Any file type is accepted: media
(video/audio) gets the full set (metadata, share, play/edit), a generic file
(pdf/zip/docx/…) is download-only.
- MediaAsset.media_kind ("video"|"audio"|"file") — the stored discriminator that
gates library actions. Set at every finalize (download probe, editor carries the
source's kind, upload probe); consolidates the ad-hoc audio-detect that lived only
in links.py into one invariant (downloads.mediakind.derive). Migration 0076 adds
the column + backfills existing rows.
- downloads/upload.py: ingest_upload probes the file (ffprobe → codecs/dims/duration),
places it in a per-user .uploads tree, and creates an already-ready asset + done job
(the same cache-hit shortcut enqueue uses). Uploads never expire (irreplaceable).
- POST /api/downloads/upload: streaming multipart with the per-file cap
(download_upload_max_bytes, default 500 MiB) enforced on actual bytes read; quota
charges the known size up front (quota.check_upload).
- Security: a generic file is always served force-download (attachment +
application/octet-stream) on both the in-app and public endpoints, so uploaded
HTML/SVG can't execute inline. Edit + redownload reject non-media / upload sources.
- python-multipart added (first multipart endpoint in the app).
Matches each mirrored Plex movie/show to TMDB by its stored canonical guid,
fetches once (append_to_response), and PERSISTS the enrichment onto the row —
served from the DB, never a live TMDB call at serve time. Additive: the
Plex-sourced imdb_rating/rating are untouched; tmdb_rating is the distinct
TMDb community score (ratings scope = TMDb + Plex's IMDb/audience, no OMDb/RT).
- config.py: tmdb_api_key + api_base/language/interval/batch defaults.
- sysconfig SPECS: tmdb_api_key (secret, Fernet) + tmdb_language, auto-rendered
in the admin Config page; read like the Plex token.
- migration 0071 (ADD-only nullable, reversible): plex_items + plex_shows gain
tmdb_id / tmdb_enriched_at (watermark) / tmdb_rating / tmdb_vote_count /
budget / revenue / keywords / crew / studios / production_countries /
recommendations / backdrops; plex_people gains tmdb_person_id (the S2
foundation for S6 person bios). No watermark reset needed.
- app/plex/tmdb.py: TmdbClient (mirrors PlexClient; throttled; 404->None,
transient->TmdbError), parse_tmdb / apply_tmdb_detail (one-parser rule),
guid_to_tmdb_id (tmdb: direct, imdb:/tvdb: via /find), enrich_batch (movies
then shows, transient error leaves the watermark NULL to retry, definitive
no-match still stamps so it isn't re-fetched), _link_people (upserts
tmdb_person_id by name), serve_block (recommendations resolved to library
rows by guid), run_enrich (no-op without a key).
- scheduler: tmdb_enrich nightly job (default 120 min, no YouTube quota),
runtime-tunable + "run now" from the Scheduler dashboard.
- detail endpoints emit `tmdb` (movies + shows) so it's curl-verifiable now;
the FE render lands in S5.
Note: _link_people inserts plex_people rows for TMDB cast/crew; unreferenced
crew (composers etc., not in cast_names/directors) get pruned by the orphan
sweep — acceptable, the person page is cast-driven and cast rows survive.
Gate: ruff + py_compile green; backend test lane FULL suite 387 passed
(incl. migration drift downgrade->re-upgrade + test_plex_tmdb 9 tests).
Frontend unchanged since S1. Not merged (epic branch, stacks on S1).
Restores CLAUDE.md's canonical transaction rule ("the handler commits; helpers
flush; only quota owns its session") on the config path: sysconfig.set_value /
sysconfig.reset and state.set_sync_paused now flush instead of committing, so a
change lands in ONE transaction with the audit row the route records for it —
previously the helper's internal commit split them, and a crash between left the
mutation persisted with no audit trail.
All callers already commit (the config PATCH/DELETE + audit, the sync pause/resume
+ audit, the scheduler maintenance PATCH); the setup wizard, which relied on the
internal commit, gets an explicit db.commit() after its loop. apply_interval is
deliberately left committing — it performs a live APScheduler reschedule that must
follow the DB persist, so it owns its own unit of work (a legitimate exception,
like the download service transitions). New test locks the flush-not-commit
contract (a rollback before the caller commits discards the change). 368 pass.
The admin-tunable maintenance re-validation batch lived in its own app_state
column with a hand-rolled override-or-default reader in app.state — a fourth
config store duplicating the sysconfig SPECS pattern. Move it to a sysconfig key
(`maintenance` group, min=100 max=100_000): the reader (sync/maintenance.py) and
the Scheduler dashboard (routes/scheduler.py PATCH + GET) now go through
sysconfig.get_int / set_value / spec, and app.state loses get/set_maintenance_batch
+ the MIN/MAX constants + the settings import. Migration 0070 carries any existing
override into the system_config store before dropping the app_state column
(reversible; restores + copies back on downgrade). Reuses the existing
sysconfig.spec() for the dashboard's min/max, so the bounds have one source.
Full lane 365 pass (migration drift + reversibility exercised), ruff clean.
This codebase leans on "why" comments as its architecture doc, so a header that
claims the opposite of the code below it is worse than none. Fix the seven the
review flagged: channels.py (subscribe/unsubscribe shipped), playlists.py +
sync/playlists.py (YouTube two-way sync + write-back shipped), setup.py (drop the
"epic 6c" ref — the wizard steps exist), config.py ("auth._client_ip" ->
"routes.auth._client_ip"), db.py ("routes/plex.py" -> "routes/plex/" after the
package split), sysconfig.py (the "Phase C" note — the watch-sync job that reads
plex_watch_sync_interval_min has landed; clarified it's a boot default, not a knob).
Docs only.
A rotated or missing TOKEN_ENCRYPTION_KEY makes every stored secret undecryptable.
sysconfig._raw_override called security.decrypt() with no guard, and it sits on
hot paths (/api/me via google_enabled, login, every YouTube scheduler job,
account purge) — so a key mismatch raised InvalidToken and 500'd the whole app,
the SPA wouldn't even boot, with no documented recovery.
Catch the decrypt failure in _raw_override -> warn once per key and fall back to
the env/config default. The YouTube client's refresh-token decrypt now raises a
clear YouTubeError ("reconnect") that every caller already handles, and
purge_user uses decrypt_optional so a best-effort revoke can't 500 the delete.
Document that the key must never change once secrets are stored (recovery: clear
the affected system_config rows and re-enter).
Adds the storage + sync for the Hungarian-metadata overlay (the browsable EN sections gain HU
twin fields written from a paired HU section, matched by guid; no browsable HU rows).
Schema (2 migrations, ADD-only; run before the first HU sync while *_hu is NULL so the generated
column build is trivial):
- 0063: plex_libraries.metadata_lang ('en' default) + self-FK overlay_of.
- 0064: plex_items/plex_shows.guid (indexed) + title_hu/summary_hu/genres_hu (+ GIN) + a STORED
generated search_vector_hu mirroring the EN vector (title_hu A / people_text B / summary_hu C) + GIN.
Sync:
- includeGuids=1 on section_items so the canonical guid rides the cheap listing.
- _canonical_guid(meta) (tmdb > imdb > tvdb) captured onto every EN row in _apply_item/_sync_shows.
- Two-pass sync(): pass 1 mirrors browsable (non-overlay) sections; pass 2 reads plex_overlay_map
('huKey:enKey', new sysconfig), designates each HU section (metadata_lang='hu' + overlay_of), and
_sync_overlay writes title_hu/summary_hu/genres_hu onto the guid-matched EN rows.
Browse: _content_libs now excludes overlay libraries (overlay_of is None); the unified_library and
facets inline library partitions fold into it, and list_libraries/collections exclude overlays too.
Tests: DB-lane coverage of the overlay write (matched vs unmatched rows, no browsable HU rows, the
generated search_vector_hu populates), the guid parse, and the browse exclusion. Full suite 272
passed; migrations verified reversible (upgrade→downgrade→upgrade). S5b (persist the live detail
fields + serve item/show detail from DB) is the follow-up.
Verified each deferred per-subsystem item against current source, then fixed the
real ones (tradeoffs left as-is, see siftlode-ops/CODE-HYGIENE.md closeout):
- search BUG-3: don't finalise shorts_probed on un-enriched stubs (enrichment
failure/omitted rows) — restores the scheduler's enriched_at guard so a real
Short can't leak into the feed and never get reclassified.
- downloads GC: 4th pass reaps orphaned errored, fileless, unreferenced assets
(they carry no TTL, so the expiry passes never cleared them).
- downloads B6: quota/edit errors now return a structured {code,reason,limit}
the trilingual client localises, instead of hardcoded English + dot-decimal GB.
- channels BB1: reset-backfill re-arms deep sync on every subscriber (bulk update)
instead of 404ing when the admin isn't personally subscribed.
- channels BB2: enrich the stub on BOTH the normal and "already exists" desync
path (nest the insert try inside the client `with`).
- channels CB3: drop the redundant second _discovery_rows read (identity-mapped
rows are already enriched; re-sort in Python for the title tie-break).
- playlists PC1: read the live playlist once in push() and share it with plan_push
+ push_playlist (halves read-quota, closes the second TOCTOU window).
- playlists PC2/PC5: batch the cover thumbnails in one window query (was N+1);
rename combines count+duration into one aggregate + a single cover lookup.
- messages MB2: get_thread only resolves a messageable partner OR one we already
share a thread with (closes the user-enumeration oracle).
- messages MB3: push a live unread-count to the user's other tabs after mark-read.
- messages MC4: list_conversations uses DISTINCT ON + grouped COUNT instead of
loading the whole message history into memory.
- config AB3: per-spec allow_empty so smtp_user/youtube_api_proxy can be blanked
to disable them rather than snapping back to the env default.
Plex records watch state per Plex account; Siftlode per user in plex_states. A new plex_link table
maps a Siftlode user to a Plex account; for the owner (MVP) the row uses the server admin token
(uses_admin=True), so no separate Plex login. app/plex/watch_sync.py reads the owner account's
viewCount/viewOffset/lastViewedAt (already present in the catalog mirror's section listing) and
upserts them into the owner's plex_states — 'Plex is master' on this first import, but only where
Plex has a watch record (Siftlode-only states are preserved; union on the intersection). Idempotent.
Admin routes: GET/POST /api/plex/watch/link (status + enable/disable; first enable runs the import)
and POST /api/plex/watch/import (re-run). Migration 0051_plex_link. Two-way push (Phase B) and the
incremental Plex→Siftlode reconcile (Phase C) build on this in later ships.
- app/plex/sync.py: full reconcile of enabled movie/show sections into plex_*
(upsert by rating_key). Reuses Plex's own codec info to classify browser
playability (direct/remux/transcode) — no ffprobe. Movies + episodes become
playable leaves; shows/seasons mirrored for the drill-down.
- routes/plex.py: GET /libraries, /browse (FTS search + sort + paging, movie
leaves or show cards), /show/{rk} (seasons+episodes, per-user state), /image
(proxies Plex art, no duplication); admin POST /sync. All auth'd, demo-allowed.
- scheduler: plex_sync job (interval settings.plex_sync_interval_min).
- Verified against the real server: 2 libs, 3206 movies, 260 shows/961 seasons/
14768 episodes synced in 13s; FTS search + drill-down work. Playability:
~1% direct, 89% remux, 6% transcode (informs P2/P3).
- Live-search results stay ephemeral: the discovery-cleanup job now also reclaims un-kept
via_search videos (no watch state / not playlisted / channel not subscribed) after a grace
period (search_grace_days), and POST /api/search/clear discards a given result set 'as if
never added' (drops the user's search-finds + deletes the now-orphaned, un-kept videos).
Admin POST /api/admin/purge-discovery runs it on demand (grace 0).
- Count selector: GET /api/search/youtube gains a 'limit' — the free scrape source pages
through continuations until that many results are gathered (no manual load-more); the API
source stays one ≤50 page (cost).
- Per-user channel blocklist (migration 0034 blocked_channels): block/unblock/list endpoints;
blocked channels' videos are dropped from live search before ingest and hidden from the feed
/ Library / explore / channel page; explore refuses a blocked channel.
- New-first ordering: results you already have (subscribed channel, watched/in-progress/saved/
playlisted) sink below genuinely-new discoveries, preserving relevance within each group.
Adds the backend for a dedicated channel page + ephemeral browsing of un-subscribed
channels:
- migration 0033: channels.{total_view_count,published_at,banner_url,external_links,
from_explore}, videos.via_explore, explored_channels (per-user, grace-clocked).
- enrich channels with part=brandingSettings (banner/links) + statistics.viewCount +
snippet.publishedAt — no extra quota.
- GET /api/channels/{id}: About detail + this user's relationship; lazy-enriches the new
About fields (published_at sentinel).
- POST /api/channels/{id}/explore (require_human, quota-reserve guarded): records the
exploration, flags the channel ephemeral unless followed, ingests one page of uploads
(via_explore) + enriches; returns next_page_token for load-more.
- feed: per-explorer gate — a via_explore video is visible only to users who explored or
subscribe to its channel, so exploration never leaks into everyone's catalog.
- subscribe = keep: clears from_explore + via_explore on the channel's videos.
- scheduler explore_cleanup job + explore_grace_days config: hard-delete explored-but-
unkept channels and their untouched ephemeral videos after a grace period.
Live YouTube search can now use YouTube's internal InnerTube endpoint instead
of search.list, materialising results through the same enrich/provenance path
at zero API quota (search.list costs 100 units/page; scrape costs nothing, only
the cheap shared videos.list enrich is charged).
- youtube/search_scrape.py: InnerTube search returning the same page shape as
YouTubeClient.search_videos (items + continuation cursor); SOCS consent cookie,
videoRenderer walk (channels/playlists/Shorts shelves naturally excluded),
type:video filter, cached InnerTube key/version with constant fallbacks.
- routes/search.py: admin-selectable source (search_source, default scrape).
Scrape path skips the 100-unit budget pre-check and logs a zero-cost search
event so the per-user daily cap still counts it; api path unchanged. Response
carries the active source.
- sysconfig/config: new search_source key (scrape|api).
- quota.log_action: record a zero-cost action event for per-user rate limits.
Add a live YouTube search that materialises results into the shared catalog so
they render with the normal feed cards + in-app player and gain per-user state.
- YouTubeClient.search_videos(): search.list (100 units), embeddable-only, returns
flat stubs + nextPageToken; surfaces liveBroadcastContent for live filtering.
- routes/search.py GET /api/search/youtube: require_human + per-user daily cap
(search_daily_limit_per_user, default 70) + can_spend pre-check (429 on either);
drops live/upcoming, upserts channel stubs (channels.list) + video stubs, enriches
(videos.list), runs the youtube.com/shorts probe, then excludes Shorts/live and
returns feed cards in relevance order with the YouTube pageToken as the cursor.
- Provenance: videos.via_search / channels.from_search (migration 0028) flag
search-discovered rows; the feed hides them from the Library (scope=all) by default
via exclude_search_discovered, leaving the Mine feed untouched.
- quota.actions_today() counts a user's per-action events today for the cap; only the
search.list call is attributed VIDEOS_SEARCH so the counter is exactly 1 per search.
New youtube_api_proxy setting (env fallback + admin Config UI, env YOUTUBE_API_PROXY):
when set, the YouTubeClient routes all its httpx traffic through that HTTP(S) proxy.
Lets a dynamic-IP host send API calls through a fixed-IP host (e.g. the server over
private tunnel) so an IP-restricted API key keeps working. Empty = direct.
- Build the Google OAuth client lazily from sysconfig (DB override, env fallback) and re-register
when the credentials change, so the install wizard / admin can set them without a restart.
- New 'google' config group (google_client_id/secret, encrypted) on the Configuration page; the
token-refresh reads the creds the same way.
- Public GET /auth/config exposes google_enabled; the login page hides 'Continue with Google'
when Google OAuth isn't configured (email+password still works).
Add email+password auth alongside Google: argon2id hashing; users gains
password_hash/email_verified/is_active and google_sub becomes nullable (migration
0022); a single-use, hashed auth_tokens table for email verification + password
reset. Registration creates a pending (inactive, unverified) account + an access
request; sign-in needs verified email AND admin approval. Anti-enumeration: uniform
register/login/reset responses (a correct-password owner still gets a specific
pending reason). allow_registration flag (DB-tunable). Admin users-list + role
endpoint (guards: not self, not demo, not the last admin); approving access (or a
manual whitelist add) now activates the matching pending account. current_user
rejects deactivated accounts. Verified end-to-end via curl + DB.
Register youtube_api_key in the sysconfig registry as a secret and resolve it from
the DB-override-or-env layer in YouTubeClient (self.db is in scope). Adds a YouTube
API group to the Configuration page (EN/HU/DE).
Google OAuth client id/secret stay env-only for now: the authlib client is
registered at module load (auth.py), and the token-refresh reads them too, so a
runtime DB override needs a lazy/re-registerable OAuth client — that belongs to the
install-wizard epic (first-boot OAuth config without restart). Admin-role-via-UI
moves to the auth-overhaul epic (user management lives there).
Register 8 more keys in the sysconfig registry (quota daily budget + backfill
reserve, recent-backfill window, shorts-probe params, enrich/autotag batch sizes)
and route their reads through the DB-override-or-env resolver at every call site
(quota.py, sync/runner.py, sync/videos.py, sync/autotag.py, sync/maintenance.py,
routes/scheduler.py). All read sites already had a db session in scope. Reads are
read-through (no cache), matching app.state; admin can tune them live, no redeploy.
Add a generic admin-editable config layer (epic 4a): system_config KV table
(migration 0021), a sysconfig registry that is the single source of truth for
DB-overridable keys (type/group/default/bounds/secret) + a DB-override-or-env
resolver, and admin endpoints (GET/PATCH/DELETE /api/admin/config + a test-email
probe). Secrets are Fernet-encrypted at rest (TOKEN_ENCRYPTION_KEY); without it
they stay env-only. First group wired end-to-end: Email/SMTP — email.py now
reads host/port/user/from/password via the resolver (own session, since email
is sent from background tasks).