2a18e91c39
Four-part change to push more surfaces onto the drift cache and eliminate cold-tab-visit latency on the Library screen. * **Library Artists tab** — _libraryArtistsProvider migrates from REST-paginated AsyncNotifier with infinite-scroll loadMore to a drift-first StreamProvider over cached_artists ordered by sortName. Sync already populates the full set; cacheFirst's fetchAndPopulate covers the fresh-install + sync-not-yet-done cold case via /api/artists?limit=1000. SWR refresh on every visit. GridView.builder lazily realizes only visible cells so loading the full list up front is fine for typical libraries. loadMore + NotificationListener gone. * **Library Albums tab** — same migration, drift-first over cached_albums joined with cached_artists for the artistName field. * **systemPlaylistsStatusProvider** — new CachedSystemPlaylistsStatus single-row table (schema 6 → 7, JSON blob like CachedHomeSnapshot) for the home Playlists row's "building / pending / failed" placeholder logic. Drift-first means the row paints with the prior status instantly instead of flickering through SystemPlaylistsStatus.empty() while the REST call resolves. * **Library screen tab pre-warm** — ref.listen on all 5 tab providers in _LibraryScreenState.build subscribes them upfront so swiping between tabs feels instant rather than each tab paying its own cold-cache cost on first visit. cacheFirst handles dedupe of concurrent fetchAndPopulate triggers. Test mock updated for the StreamProvider type change on systemPlaylistsStatusProvider.