refactor(decouple): move coerceOpenArtistRefs to lib/api (off artist feature)

First step of decoupling the audio core from feature imports. coerceOpenArtist
Refs is a pure Subsonic-response normalizer (one-object-vs-array quirk) that was
mis-membered in features/artist but consumed by the audio core (songToTrack,
trackArtistRefs) and others. Relocate it beside its SubsonicOpenArtistRef type in
lib/api/; drop the artist-barrel re-export; repoint the 4 barrel consumers.

Removes the @/features/artist runtime edge from the audio core (utils/playback)
entirely. tsc 0, lint 0/0, suite 319/2353 green.

(composerBrowseSessionStore's ALL_SENTINEL import from @/features/artist remains
— that's a non-audio global browse store, separate from this decouple.)

src/components/PlayerBar.tsx

@@ -22,7 +22,7 @@ import PlaybackDelayModal from './PlaybackDelayModal';
 import { usePlaybackScheduleRemaining } from '../utils/format/playbackScheduleFormat';
 import { usePreviewStore } from '../store/previewStore';
 import { usePerfProbeFlags } from '../utils/perf/perfFlags';
-import { coerceOpenArtistRefs } from '@/features/artist';
+import { coerceOpenArtistRefs } from '@/lib/api/openArtistRefs';
 import { resolveTrackArtistRefs } from '../utils/playback/trackArtistRefs';
 import { PlayerTrackInfo } from './playerBar/PlayerTrackInfo';
 import { PlayerTransportControls } from './playerBar/PlayerTransportControls';

src/features/album/utils/deriveAlbumHeaderArtistRefs.ts

@@ -1,5 +1,5 @@
 import type { SubsonicAlbum, SubsonicOpenArtistRef, SubsonicSong } from '@/lib/api/subsonicTypes';
-import { coerceOpenArtistRefs } from '@/features/artist';
+import { coerceOpenArtistRefs } from '@/lib/api/openArtistRefs';
 
 function nonEmpty(refs: SubsonicOpenArtistRef[]): refs is SubsonicOpenArtistRef[] {
   return refs.length > 0;

src/features/artist/index.ts

@@ -27,7 +27,6 @@ export * from './store/artistAlbumYearSortStore';
 export * from './store/artistBrowseSessionStore';
 export * from './store/artistLayoutStore';
 export * from './utils/artistsHelpers';
-export * from './utils/openArtistRefs';
 export * from './utils/runArtistDetailActions';
 export * from './utils/runArtistDetailPlay';
 export * from './utils/sortArtistAlbums';

src/lib/api/openArtistRefs.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { coerceOpenArtistRefs } from '@/features/artist/utils/openArtistRefs';
+import { coerceOpenArtistRefs } from '@/lib/api/openArtistRefs';
 
 describe('coerceOpenArtistRefs', () => {
   it('returns an empty array for nullish input', () => {

src/utils/playback/songToTrack.ts

@@ -1,6 +1,6 @@
 import type { SubsonicSong } from '@/lib/api/subsonicTypes';
 import type { Track } from '../../store/playerStoreTypes';
-import { coerceOpenArtistRefs } from '@/features/artist';
+import { coerceOpenArtistRefs } from '@/lib/api/openArtistRefs';
 import { activeServerProfileId } from './trackServerScope';
 
 export function songToTrack(song: SubsonicSong): Track {

src/utils/playback/trackArtistRefs.ts

@@ -1,6 +1,6 @@
 import type { SubsonicOpenArtistRef } from '@/lib/api/subsonicTypes';
 import type { Track } from '../../store/playerStoreTypes';
-import { coerceOpenArtistRefs } from '@/features/artist';
+import { coerceOpenArtistRefs } from '@/lib/api/openArtistRefs';
 
 type TrackArtistFields = Pick<Track, 'artist' | 'artistId' | 'artists'>;