v3.6.0

v3.6.0: Hover preview tooltips, tag preview, fix garbled emoji

- Hover preview: matched songs show Spotify album art, track name, artist, album on hover
- Tag preview: songs appear with hourglass icon immediately as tags are read, before matching
- Enriched search: search_with_fallback returns full Spotify metadata (name, artist, album, image)
- Fixed garbled Unicode in duplicate remover (artist prefix, count, Fix button, success message)
- Changed no_match event to fail for consistency across all backends
- Added scanned_tag event to main.py, retry_failed.py, youtube_import.py
- CSS tooltip with glassmorphism, fade-in animation, album art thumbnail