feat: queue-ux-improvements (#419)

* feat(queue): add ETA display, equalizer indicator and collapsible now playing

* deleted endsAt and showDuration strings, changed eta update to 30s

* feat(queue): ETA tooltip, persistent Now Playing collapse, EQ bar pause, remove redundant Play icon

* feat(queue): fold ETA into existing total/remaining toggle as third mode

The standalone ETA span next to the track counter is removed; instead the
clickable duration label in the queue header now rotates through three
modes per click: total → remaining → eta → total. Counter (N/M) stays
where it was.

ETA mode keeps the live-feel treatment from the original PR (accent
colour while playing, muted at 50% opacity when paused). The other two
modes use plain accent.

i18n: queue.etaTooltip removed (no longer a separate descriptive label),
queue.showEta added as the action tooltip ('Show estimated end time')
in all 8 locales — matches the showRemaining / showTotal pattern.

* docs(changelog): add #419 queue UX improvements entry

Adds the [1.45.0] / Added entry for this PR's queue panel refinements
(position counter, tri-state duration toggle including ETA, collapsible
Now Playing section, animated EQ indicator).

---------

Co-authored-by: Psychotoxical <171614930+Psychotoxical@users.noreply.github.com>

src/store/previewStore.ts

@@ -21,15 +21,6 @@ interface PreviewState {
   elapsed: number;
   /** Total preview window in seconds (echoes the duration_sec arg). */
   duration: number;
-  /**
-   * True only after the engine has emitted `audio:preview-start` for the
-   * current `previewingId` — i.e. audio is actually playing. Drives the
-   * progress-ring animation so the ring doesn't run ahead of the speaker
-   * during the engine's download/decode/seek warmup. Reset to false on every
-   * `startPreview` call so a switch from track A to track B doesn't carry
-   * over A's animation state.
-   */
-  audioStarted: boolean;
 
   startPreview: (song: { id: string; title: string; artist: string; coverArt?: string; duration?: number }, location: TrackPreviewLocation) => Promise<void>;
   stopPreview: () => Promise<void>;
@@ -49,7 +40,6 @@ export const usePreviewStore = create<PreviewState>((set, get) => ({
   previewingTrack: null,
   elapsed: 0,
   duration: 30,
-  audioStarted: false,
 
   startPreview: async (song, location) => {
     const auth = useAuthStore.getState();
@@ -87,7 +77,6 @@ export const usePreviewStore = create<PreviewState>((set, get) => ({
       previewingTrack: { id: song.id, title: song.title, artist: song.artist, coverArt: song.coverArt },
       elapsed: 0,
       duration: previewDuration,
-      audioStarted: false,
     });
 
     try {
@@ -101,7 +90,7 @@ export const usePreviewStore = create<PreviewState>((set, get) => ({
     } catch (e) {
       // Roll back optimistic state on failure.
       if (get().previewingId === song.id) {
-        set({ previewingId: null, previewingTrack: null, elapsed: 0, audioStarted: false });
+        set({ previewingId: null, previewingTrack: null, elapsed: 0 });
       }
       throw e;
     }
@@ -113,19 +102,15 @@ export const usePreviewStore = create<PreviewState>((set, get) => ({
       await invoke('audio_preview_stop');
     } catch {
       /* engine will emit preview-end anyway; clear locally as fallback */
-      set({ previewingId: null, previewingTrack: null, elapsed: 0, audioStarted: false });
+      set({ previewingId: null, previewingTrack: null, elapsed: 0 });
     }
   },
 
   _onStart: (id) => {
-    const current = get().previewingId;
-    if (current !== id) {
+    if (get().previewingId !== id) {
       // Engine fired start for an id we didn't track locally — keep id but
       // leave previewingTrack as-is (the caller's startPreview() set it).
-      set({ previewingId: id, elapsed: 0, audioStarted: true });
-    } else {
-      // Audio is now actually playing — unblock the progress-ring animation.
-      set({ audioStarted: true });
+      set({ previewingId: id, elapsed: 0 });
     }
   },
 
@@ -136,6 +121,6 @@ export const usePreviewStore = create<PreviewState>((set, get) => ({
 
   _onEnd: (id) => {
     if (get().previewingId !== id) return;
-    set({ previewingId: null, previewingTrack: null, elapsed: 0, audioStarted: false });
+    set({ previewingId: null, previewingTrack: null, elapsed: 0 });
   },
 }));