New "Sync" button in the enhanced view header validates an artist's
library entries against files on disk. Removes stale tracks (missing
files), cleans empty albums, and updates track counts.
- POST /api/library/artist/<id>/sync endpoint
- Checks each track's file_path via _resolve_library_file_path
- Empty album cleanup checks ALL tracks (not just this artist's)
to avoid deleting albums shared with other artists
- Toast shows results: stale removed, albums cleaned, or "All files
verified" if everything checks out
- Auto-refreshes enhanced view when changes are made
326bb548ce
