Playlist cards (carousels, search, favorites) emitted ("playlist","queue")
and ("playlist","play-next") but no handler existed, so the menu items
were dead. Add enqueue_playlist (fetch the playlist's tracks by id and
append, or insert-next in reverse to keep order) and the two match arms.
The album/track enqueue paths already worked but gave no visible feedback
when the queue panel was closed, reading as "unwired" — add a success
toast (Added to queue / Playing next) to every enqueue path.
cc
vicrodh
c6c113d3f9