The grid now displays the user's per-song title/artist/album/year override
in place of the pack value ("grid shows only overrides") — a matched
MusicBrainz canon never silently re-titles a card; canon stays in the
Details drawer + art. Overlaid in Python over the visible window, keyset-safe
like the P4 artist-alias re-label: the seek still runs on the raw column, and
the one overridable keyset column (title) stashes its raw value for the cursor
so paging never skips/dupes. The private stash is dropped from the payload.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Backend foundation for the Fix-metadata popup. Not yet surfaced in the UI (the
display + 3-tab popup are the next slices); no PR until it's user-visible.
Slice 1 — the store:
- `song_field_override(filename, field, value, locked)` table: a reversible
DISPLAY overlay (never written to the pack), filename-keyed so it survives a
rescan (never purged by delete_missing) and is dropped only with the song.
- DB methods (partial upsert that drops empty+unlocked rows; batch map) +
`GET`/`PUT /api/song/{fn}/overrides` (field allowlist title/artist/album/
year/genre; clearing rides PUT since DELETE /api/song/{path} shadows sub-
routes; PUT demo-blocked).
Slice 2 — locks respected by enrichment:
- The auto-matcher composes a per-song `_compose_lock_filter` onto the global
apply-filter, so a match still applies IDENTITY (mbid/release → art) but never
re-canonicalizes a LOCKED display field.
- Gap-fill (write-to-file) skips locked album/year/genre — writing the matched
value would be exactly the clobber the lock exists to prevent.
- Review/manual picks bypass the filter (an explicit confirm overrides a lock).
Tests: store semantics + rescan-survival + API; the lock filter + reader; an
auto-match leaving a locked field un-canonicalized; gap-fill excluding locked
keys.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
