Deep-review round 4, the "one report per failure" contract round 3 introduced.
- `req` marked gateway (502/503/504) and network failures "already reported" because they raise
the connection notice. But that notice is about connectivity and removes itself on the very next
answer — which every caller's own resync refetch fetches at once — so a delete that hit a
keepalive reset flashed the notice and was then reported nowhere, the list still there. Only the
durable reports (the error dialog, the 401 sign-out) count now; the caller says the action failed.
- A connection notice the user closed swallowed every later one for the rest of the visit; it is
raised again.
- `req` and `uploadReq` share one failure policy (`reportFailure`). The upload copy had drifted: a
502 opened the blocking "Server error (502)" dialog and cleared a notice that was still true.
- A taken Plex collection name is a structured 409, localized, and the create/rename calls are
quiet: it was an English dialog plus a Hungarian toast. `notifyCollectionEditError` is gone.
- The mutation onErrors that toasted unconditionally after a non-quiet request (invite approve /
deny / add, demo whitelist, audit clear, scheduler, share, full history, edit, config tests, tag
attach) go through `notifyActionError`; the playlist delete's hand-rolled copy of it too (it takes
a level now). The user role / suspend / delete actions had no onError at all: a user deleted in
another tab failed silently and stayed listed — now said, and the list refetched.
Deep-review round 3 of bug hunt 2026-09.
- get_or_404 / owned_or_404 answer a structured {code: "not_found", reason: <what>}
(errors.notFound.* in HU+EN, generic fallback). The structured-404 fix of round 2 had gone into the
ad-hoc `_own_playlist` (CLAUDE.md's "Not" pattern) while the shared helpers stayed string-only, so
views, tags, pins, Plex playlists, invites and users still 404'd in English. `_own_playlist` now
goes through owned_or_404; admin's hand-rolled user lookups use get_or_404.
- A move into a list that is gone names the TARGET (reason "move_target") — "this playlist doesn't
exist any more" was read as the list on screen, which still exists.
- Every refusal in the playlists router is a {code: "playlist", reason} (playlists.errors.* HU+EN)
instead of a bare English string shown verbatim in the Hungarian UI.
- `req` / `uploadReq` mark the errors they already put on screen (the error dialog, the connection
notice, the 401 sign-out), and notifyActionError skips those. The watched toggles, the saved views
and a playlist delete toasted a fault the dialog was already showing; Playlists' two hand-written
status filters now go through the same check.
- D3 snapshotted the removal's TARGET, but whether the player offered Remove still followed the
selected list: launched from Watch later (no Remove, by design), selecting another list under it
made Remove appear — and delete from Watch later. The snapshot now carries the launch list's
editability too.
- Selecting another list under an open player (the command palette works over it) put the page into
"Loading…", and the player was rendered only in the loaded branch — it vanished mid-playback and
came back at its launch video. It now sits at one place in the tree whatever the page is doing.
- A removal takes the video out of the CACHED list as well as the rows: the player's progress
checkpoint rewrote that entry before the refetch landed, handing the membership guard a list that
still held the video — the row came back and the undo history went.
- The watched-state callback refreshed the selected list, not the launch list (D3's sibling).
- `_own_playlist`'s 404 is structured (`{"code": "playlist", "reason": "not_found"}`) and localised:
the bare "Unknown playlist" reached the Hungarian UI in English, which also made round 1's new
`removeFailed` string unreachable. Both Remove and Move report through `notifyActionError` now.
- The "viewer moved on under the confirm" test stepped back only once, which lands on the same video
whether or not the removed one left the queue; it now takes the second step that tells them apart.
Deep-review remediation on the frontend, all findings adversarially verified:
- LibraryPlayer picks audio vs video from the canonical media_kind (single source), not a
hardcoded container whitelist, so an uploaded audio file with an uncommon/absent container
renders in <audio> instead of a broken video box (legacy null media_kind keeps the heuristic).
- UploadDialog aborts the in-flight upload when the dialog is closed by X/ESC/backdrop/Back
(not only the footer Cancel); drag highlight uses an enter/leave depth counter to stop the
flicker; the progress bar gets a stable role=progressbar aria-label with the value on aria-valuenow.
- DownloadCenter's Shared tab renders honest loading/error states instead of a blank panel, and
the library/shared row-action gating moves to a single tested helper (lib/downloadActions).
Tests: downloadActions gating matrix, the uploadReq XHR path (abort/401/422-localize/onerror),
and the media_kind-driven audio/video branch.
i18n: downloads.upload.uploadProgress (HU + EN).