refactor(queue): co-locate QueuePanel UI into features/queue

Extract the queue UI (QueuePanel + queuePanel/* components + useQueue* hooks)
into features/queue/ with a barrel. This is the chosen playback/queue boundary:
queue = the QueuePanel UI that CONSUMES the playback store; queue STATE and the
audio engine stay in store/ (playback-core, moved separately). Verified
one-way: no playback-core file imports the queue UI back (only doc comments
mention it).

Excluded as NOT queue-UI: useIdlePlayQueuePull (AppShell) and
usePlayQueueSyncLedState (ConnectionIndicator) are queue-SYNC orchestration,
not panel UI — left in hooks/ to move with playback.

Pure move. One test fix: QueuePanel.test.tsx reads its subject via a hardcoded
readFileSync('src/components/QueuePanel.tsx') path (architecture-pin grep for
forbidden HTML5 DnD) — repointed to the new location (the move tool can't
rewrite non-import string paths). tsc 0, lint 0/0, suite 319/2353 green.

src/features/queue/hooks/useQueueTrackEnrichment.ts

@@ -0,0 +1,102 @@
+import { useEffect, useState } from 'react';
+import { listen } from '@tauri-apps/api/event';
+import { libraryGetFacts, libraryGetTrack } from '@/lib/api/library';
+import { usePlaybackServerId } from '@/hooks/usePlaybackServerId';
+import { useLibraryIndexStore } from '@/store/libraryIndexStore';
+import {
+  enrichmentDisplayComplete,
+  OXIMEDIA_MOOD_UI_ENABLED,
+  parseTrackEnrichmentFacts,
+  type ParsedTrackEnrichment,
+} from '@/utils/library/trackEnrichment';
+import { libraryIsReady } from '@/utils/library/libraryReady';
+import { normalizeAnalysisTrackId } from '@/utils/playback/queueIdentity';
+
+const EMPTY: ParsedTrackEnrichment = {
+  serverBpm: null,
+  measuredBpm: null,
+  moodLabels: [],
+};
+
+/** Enrichment may finish several seconds after CPU seed / playback start. */
+const REFETCH_MS = [3_000, 8_000, 15_000, 30_000, 60_000] as const;
+
+const ENRICHMENT_FACT_KINDS = OXIMEDIA_MOOD_UI_ENABLED
+  ? (['bpm', 'moods', 'mood_tag', 'mood_labels', 'valence', 'arousal'] as const)
+  : (['bpm'] as const);
+
+/**
+ * Loads server BPM + oximedia mood facts for the queue "now playing" block.
+ * Uses the playback server id (queue scope), not the browsed server.
+ */
+export function useQueueTrackEnrichment(trackId: string | undefined): ParsedTrackEnrichment {
+  const serverId = usePlaybackServerId();
+  const indexEnabled = useLibraryIndexStore(s =>
+    serverId ? s.isIndexEnabled(serverId) : false,
+  );
+  const [data, setData] = useState<ParsedTrackEnrichment>(EMPTY);
+  const [refreshNonce, setRefreshNonce] = useState(0);
+
+  useEffect(() => {
+    if (!serverId || !trackId || !indexEnabled) {
+      // React Compiler set-state-in-effect rule: state set from a timer/animation callback.
+      // eslint-disable-next-line react-hooks/set-state-in-effect
+      setData(EMPTY);
+      return;
+    }
+
+    let cancelled = false;
+    const timers: ReturnType<typeof setTimeout>[] = [];
+
+    const load = async () => {
+      if (!(await libraryIsReady(serverId))) return;
+      try {
+        const [track, facts] = await Promise.all([
+          libraryGetTrack(serverId, trackId),
+          libraryGetFacts(serverId, trackId, [...ENRICHMENT_FACT_KINDS]),
+        ]);
+        if (cancelled) return;
+        const parsed = parseTrackEnrichmentFacts(facts, track?.bpm ?? null);
+        setData(parsed);
+        if (enrichmentDisplayComplete(parsed)) {
+          for (const id of timers) clearTimeout(id);
+          timers.length = 0;
+        }
+      } catch {
+        if (!cancelled) setData(EMPTY);
+      }
+    };
+
+    void load();
+    for (const ms of REFETCH_MS) {
+      timers.push(setTimeout(() => { void load(); }, ms));
+    }
+
+    return () => {
+      cancelled = true;
+      for (const id of timers) clearTimeout(id);
+    };
+  }, [serverId, trackId, indexEnabled, refreshNonce]);
+
+  useEffect(() => {
+    if (!serverId || !trackId || !indexEnabled) return;
+
+    let unlisten: (() => void) | undefined;
+    void listen<{ trackId: string; serverId: string }>('analysis:enrichment-updated', ({ payload }) => {
+      if (!payload?.trackId) return;
+      const eventTrackId = normalizeAnalysisTrackId(payload.trackId);
+      const currentId = normalizeAnalysisTrackId(trackId);
+      if (!eventTrackId || eventTrackId !== currentId) return;
+      if (payload.serverId && payload.serverId !== serverId) return;
+      setRefreshNonce(n => n + 1);
+    }).then(fn => {
+      unlisten = fn;
+    });
+
+    return () => {
+      unlisten?.();
+    };
+  }, [serverId, trackId, indexEnabled]);
+
+  return data;
+}