Power-user escape hatch on the Discovery Fix Track Match modal — when
fuzzy auto-search ranks the wrong recording among many same-title
versions (10 remasters, live cuts, alt sessions), paste the MusicBrainz
recording URL or bare UUID into the new field and resolve straight to
that record.
Layout:
- Shape adapter `get_recording_flat(mbid)` lives in
`core/musicbrainz_search.py` next to existing `get_track_details`.
Returns the flat Fix-popup track shape (artists as `string[]`,
album as string, single `image_url`) — distinct from the
Spotify-shaped nested dict `get_track_details` returns.
- New route `GET /api/musicbrainz/recording/<mbid>` is a thin wrapper:
validates MBID format with an anchored UUID regex, calls the adapter,
returns 400 / 404 / 200 with no inline shape massaging.
- Frontend `parseMusicBrainzMbid()` lives in `shared-helpers.js` —
pure URL/UUID parser, reusable from other surfaces (failed-MB cache,
manual match) without duplication.
- Fix modal HTML gets one new input row + button; existing search row
and result render pipeline are untouched. New `lookupDiscoveryFixByMbid()`
fetches the endpoint and feeds the single result through the existing
`renderDiscoveryFixResults` -> confirm-dialog -> match pipeline, so MB-
paste matches go through the exact same selection flow as auto-search
results.
- Enter-key bound on the MBID input via a separate handler ref so its
lifecycle matches the search-input handlers without conflating the
two submit targets.
7 unit tests cover the adapter: happy path, empty/None MBID, MB returns
None, recording-without-release (empty album), multi-artist credits,
includes-list contract, and client-error swallow.
Out of scope: the Fix popup's fuzzy cascade is still hardcoded to
spotify/deezer/itunes regardless of which primary source the user has
configured. Adding MB to that cascade (when MB is the active primary)
is a separate concern.
Discord report (CJFC, 2026-04-26): syncing a Spotify playlist to the
server overwrote anything manually added to the server-side playlist.
The fix adds a per-sync mode picker next to the Sync button on the
playlist details modal — Replace (default, current delete-recreate
behavior) or Append only (preserves existing tracks, only adds new
ones). Useful when the source platform caps playlist size and the
user is manually building beyond it on the server.
Implementation:
* New `append_to_playlist(name, tracks)` method on Plex / Jellyfin /
Navidrome clients. Each uses the server's NATIVE append API:
- Plex: `existing_playlist.addItems(new_tracks)`
- Jellyfin: `POST /Playlists/<id>/Items?Ids=...&UserId=...`
- Navidrome: Subsonic `updatePlaylist?songIdToAdd=...`
Falls back to `create_playlist` when the playlist doesn't exist
yet (first sync). No delete-recreate, no backup playlist created
(preserves playlist creation date + metadata + non-soulsync-managed
tracks).
* Dedup-by-server-native-id (ratingKey for Plex, GUID for Jellyfin,
song-id for Navidrome) — never re-adds a track already on the
playlist. Server-native identity, not fuzzy title+artist match,
so it can't false-collide.
* `sync_service.sync_playlist` accepts `sync_mode='replace'|'append'`
kwarg. Single if/else branch dispatches to `append_to_playlist` or
`update_playlist`. Threaded through `core/discovery/sync.run_sync_task`
and the `/api/sync/start` HTTP handler. Validation on the API rejects
unknown mode strings (defaults to 'replace').
* Frontend: per-playlist `<select id="sync-mode-${id}">` rendered next
to the Sync button in both modal renderers (sync-spotify.js for
Spotify playlists, sync-services.js for Deezer ARL playlists).
`startPlaylistSync` reads the select at click time; missing select
(other callers like discover.js) defaults to 'replace' so backward
compat preserved without per-call-site updates.
* SoulSync standalone has no playlist methods at all and the modal
hides the Sync button entirely on it via `_isSoulsyncStandalone` —
dispatch never reaches that path, no defensive fallback needed.
15 new tests pin per-server append behavior:
- missing playlist → create_playlist delegation
- dedup filtering (existing IDs skipped, only new tracks added)
- empty new-track set short-circuits without API call
- failure paths return False without raising
- contract listing (KNOWN_PER_SERVER_METHODS includes
'append_to_playlist'; Plex / Jellyfin / Navidrome all implement)
Plus tests/discovery/test_discovery_sync.py fake `sync_playlist`
fixture got `sync_mode='replace'` default to match the new signature
(was breaking after the kwarg add; now passing).
WHATS_NEW entry under new '2.6.0' block (hidden by
`_getLatestWhatsNewVersion` until next release bump).
Closes CJFC discord request.
