refactor(playback): move thin-state queue resolver out of utils/library into the feature

The queue-resolver family (queueTrackResolver, queueRestore, queueItemRef,
queueTrackView) runtime-imports usePlayerStore / playerStoreTypes — it is the
playback engine's thin-state queue subsystem, not shared library infra. It sat
in utils/library only because it queries the local index. Co-locate into
features/playback/store so those edges become intra-feature; its remaining deps
(advancedSearchLocal, libraryReady, serverLookup, serverIndexKey, authStore) are
plain core/infra (feature -> infra, no inversion).

Removes 4 of the 6 store/utils -> feature runtime inversions that blocked the
utils/library -> lib move. 8 files moved, 46 consumers rewritten. tsc 0, lint 0,
targeted suites green.

src/features/playback/store/queueTrackView.test.ts

@@ -0,0 +1,52 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { usePlayerStore } from '@/features/playback/store/playerStore';
+import type { QueueItemRef, Track } from '@/features/playback/store/playerStoreTypes';
+import { seedQueueResolver, _resetQueueResolverForTest } from '@/features/playback/store/queueTrackResolver';
+import { resolveQueueTrack, getQueueTracksView } from './queueTrackView';
+
+const track = (id: string, over: Partial<Track> = {}): Track =>
+  ({ id, title: id, artist: 'A', album: 'Al', albumId: 'Al', duration: 1, ...over });
+const ref = (trackId: string, over: Partial<QueueItemRef> = {}): QueueItemRef =>
+  ({ serverId: 's1', trackId, ...over });
+
+describe('queueTrackView', () => {
+  beforeEach(() => {
+    _resetQueueResolverForTest();
+    usePlayerStore.setState({ starredOverrides: {}, userRatingOverrides: {} });
+  });
+
+  it('resolves from the resolver cache when present', () => {
+    seedQueueResolver('s1', [track('t1', { title: 'Cached' })]);
+    expect(resolveQueueTrack(ref('t1')).title).toBe('Cached');
+  });
+
+  it('falls back to the provided Track on cache miss', () => {
+    expect(resolveQueueTrack(ref('t2'), track('t2', { title: 'Fallback' })).title).toBe('Fallback');
+  });
+
+  it('returns a placeholder on miss with no fallback', () => {
+    const r = resolveQueueTrack(ref('t3'));
+    expect(r.id).toBe('t3');
+    expect(r.title).toBe('…');
+  });
+
+  it('carries the ref queue-only flags onto the resolved track', () => {
+    seedQueueResolver('s1', [track('t4')]);
+    const r = resolveQueueTrack(ref('t4', { radioAdded: true }));
+    expect(r.radioAdded).toBe(true);
+  });
+
+  it('merges session star/rating overrides', () => {
+    seedQueueResolver('s1', [track('t5')]);
+    usePlayerStore.setState({ starredOverrides: { t5: true }, userRatingOverrides: { t5: 4 } });
+    const r = resolveQueueTrack(ref('t5'));
+    expect(!!r.starred).toBe(true);
+    expect(r.userRating).toBe(4);
+  });
+
+  it('getQueueTracksView resolves each ref, preferring cache then fallback', () => {
+    seedQueueResolver('s1', [track('a', { title: 'CachedA' })]);
+    const out = getQueueTracksView([ref('a'), ref('b')], [track('a'), track('b', { title: 'FbB' })]);
+    expect(out.map(t => t.title)).toEqual(['CachedA', 'FbB']);
+  });
+});