cover.jpg was always written from Spotify/iTunes URL (640x640) when the
first track in an album reached _download_cover_art before MusicBrainz
lookup completed. Later tracks with MBID skipped because file existed.
Fix: when cover.jpg exists but is small (<200KB) and we now have a CAA
MBID, attempt to upgrade it with the high-res CAA version. If CAA fetch
fails, keep existing cover — no pointless overwrites.
Also adds Forgot PIN recovery to the profile selection PIN dialog,
reusing the same credential verification flow as the launch lock screen.
Backend reset endpoint now accepts profile_id parameter.
58ee8d8a8a
