- Replace SharedPreferences with SQLite (AppStateDatabase, LibraryCollectionsDatabase) for download queue, library collections, and recent access history
- Add Set-based O(1) track containment checks for wishlist, loved, and playlist tracks
- Add batch addTracksToPlaylist with PlaylistAddBatchResult
- Go backend: strict mode locks download to selected provider when auto fallback is off
- Go backend: fix extension progress normalization (percent/100) and lifecycle tracking
- Go backend: case-insensitive provider ID matching throughout fallback chain
- Lyrics embedding now respects lyricsMode setting (embed/both/off)
- Debounced queue persistence to reduce write frequency
- Fix shouldUseFallback logic to not be gated by useExtensions
zarzet