Move audio member selection logic from frontend to backend. The frontend was probing multiple candidate audio files with error/retry logic, often resulting in 404s. Now the backend resolves the best available audio file (preview.ogg, stems/full.ogg, or any stem) during metadata extraction and includes it in song metadata as `audio_member`. The frontend makes a single, guaranteed request instead of multiple probes. Simplifies the preview flow and improves reliability.
Signed-off-by: Kyle <kyle.j.t@live.co.uk>
Implement optional audio preview when hovering over songs in the Folders view. Features include:
- Toolbar toggle button (off by default) to enable/disable hover preview
- ~0.5s dwell delay to avoid accidental audio playback while scrolling
- Dedicated <audio> element (never touches main player)
- Equalizer indicator animation overlay on song art while playing
- Per-surface localStorage persistence
- Automatic fallback through preview.ogg → stems/full.ogg → stems/audio.mp3
Bump Folder Library from 1.8.0 to 1.9.0. Remove 'auto play on hover' from roadmap as it's now implemented.
Signed-off-by: Kyle <kyle.j.t@live.co.uk>