perf: reduce CPU usage and unify next-track buffering settings

- Throttle audio:progress from 100ms to 500ms; WaveformSeek and
  FsSeekbar use imperative DOM updates instead of React re-renders
- Fix all usePlayerStore() calls without selectors across pages and
  components (useShallow / individual selectors throughout)
- Remove filter:blur and transform:scale from Hero, AlbumDetail and
  FullscreenPlayer backgrounds — eliminated expensive software
  compositing layers on WebKitGTK
- Replace translate3d with 2D translate in FS mesh and portrait
  animations; remove will-change:transform from mesh blobs
- Move Hot Cache section from Storage tab to Audio tab; group Preload
  and Hot Cache under a shared 'Next Track Buffering' section with a
  mutual-exclusivity note and auto-disable logic
- Add 'off' toggle to Preload (replaces Off button with toggle switch);
  enabling either method now automatically disables the other

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/Playlists.tsx

@@ -15,7 +15,7 @@ function formatDuration(seconds: number): string {
 export default function Playlists() {
   const { t } = useTranslation();
   const navigate = useNavigate();
-  const { playTrack } = usePlayerStore();
+  const playTrack = usePlayerStore(s => s.playTrack);
   const touchPlaylist = usePlaylistStore((s) => s.touchPlaylist);
   const removeId = usePlaylistStore((s) => s.removeId);