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/InternetRadio.tsx

@@ -19,7 +19,10 @@ import { showToast } from '../utils/toast';
 
 export default function InternetRadio() {
   const { t } = useTranslation();
-  const { playRadio, stop, currentRadio, isPlaying } = usePlayerStore();
+  const playRadio = usePlayerStore(s => s.playRadio);
+  const stop = usePlayerStore(s => s.stop);
+  const currentRadio = usePlayerStore(s => s.currentRadio);
+  const isPlaying = usePlayerStore(s => s.isPlaying);
 
   const [stations, setStations] = useState<InternetRadioStation[]>([]);
   const [loading, setLoading] = useState(true);