A Plex album_key is a hash of artist+album, so two distinct Plex albums
that share a title (e.g. a matched album plus loose files added as a second
album) collapsed into one cache album and their tracks interleaved
(1,1,2,2,...) in the album view with no way to pick a version.
Capture parentRatingKey (the real per-album Plex id) on sync, store it in a
new plex_cache_tracks column, and key the album-view version grouping on it
so each Plex album becomes its own version in the existing header picker
(best quality first). Pre-resync rows lack the column and fall back to the
old single-group behaviour; a re-sync backfills it.
cc
vicrodh
1409c9d917