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/pages/ArtistDetail.tsx

@@ -82,7 +82,6 @@ export default function ArtistDetail() {
   const currentTrack = usePlayerStore(state => state.currentTrack);
   const isPlaying = usePlayerStore(state => state.isPlaying);
   const previewingId = usePreviewStore(s => s.previewingId);
-  const previewAudioStarted = usePreviewStore(s => s.audioStarted);
   const downloadArtist = useOfflineStore(s => s.downloadArtist);
   const bulkProgress = useOfflineJobStore(s => s.bulkProgress);
   const activeServerId = useAuthStore(s => s.activeServerId) ?? '';
@@ -738,7 +737,7 @@ export default function ArtistDetail() {
                   </button>
                   <button
                     type="button"
-                    className={`playlist-suggestion-preview-btn${previewingId === song.id ? ' is-previewing' : ''}${previewingId === song.id && previewAudioStarted ? ' audio-started' : ''}`}
+                    className={`playlist-suggestion-preview-btn${previewingId === song.id ? ' is-previewing' : ''}`}
                     onClick={e => { e.stopPropagation(); usePreviewStore.getState().startPreview({ id: song.id, title: song.title, artist: song.artist, coverArt: song.coverArt, duration: song.duration }, 'artist'); }}
                     data-tooltip={previewingId === song.id ? t('playlists.previewStop') : t('playlists.preview')}
                     aria-label={previewingId === song.id ? t('playlists.previewStop') : t('playlists.preview')}