Deep-review round 4, backend half.
- The periodic HLS reaper (round 3) applied the "finished and unfetched for 30 s" rule that only a
NEW session request may apply. A remux finishes long before the film, and a paused player with a
full buffer fetches nothing, so a one-minute pause killed the session and playback died ~30 s after
resuming. The periodic pass is `reap_abandoned` now (the long idle limit, finished or not).
- A subtitle `publish` that could not keep its output (full / read-only cache volume) returned
quietly, so every poll queued the window and the whole-container pass again. It reports failure
and the pass is backed off like a failed read; a cached VTT that cannot be READ is answered
`unavailable` (`cache_unreadable`) instead of scheduling reads that can never land.
- The subtitle routes bound `rating_key` / `sub_ord` (they become a cache file name: a 250-digit
one was ENAMETOOLONG, which pathlib's exists() re-raises -> a 500), and the cache helpers no longer
throw on such a name.
- One app-wide handler turns psycopg's "text fields cannot contain NUL" DataError into a 422: round 3
guarded only the by-rating_key lookup, and `contains=`, `contains_group=`, reorder/bulk key lists
and the collection search still 500'd.
- The hand-written `db.get(...) is None -> 404 "Unknown ..."` siblings use `get_or_404` with a
`what` (channel / video / user), so the Hungarian UI no longer shows English for a gone row.
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.
peter