Walks <root>/<artist>/<source>/ (known yt-dlp source folders only; skips Lidarr
album dirs), re-queries each file's source by the [id] in its filename, and fixes
tags (album/year/artist/title) via mutagen. Honors --dry-run for preview. CLI-only
(not the REST API). Fixes downloads that landed with missing album / wrong year.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
