Release notes for 1.2.8 explaining Mixtape vs Collection vs Playlist in
user-facing terms: playlists are Qobuz-hosted track lists, Mixtapes are
private ordered cross-source listening sessions, Collections are
private themed album shelves. Covers the Discography Builder, the
Add to Mixtape picker kind rules, custom covers, duplicate-handling
dialog, and the under-the-hood notes for upgraders (new tables, new
v2_* command surface, Plex queue resolver branch).
cc