All five branch shapes of GET /collections/:id now build cards via the
cards.go adapters: smart (BookCardsFromMediaItems), system-query (same
— gains format_group/badge it previously dropped), scoped
(BookCardsFromCollectionDashRows with the Excluded filter kept), and
the all-libraries branch whose rows distinguish ID vs MediaItemID
(BookCardsFromCollectionItemRows). LibraryTypeMap hoisted to once per
page; both []BookInfo{} error seeds die with the adapters' non-nil
empties.
John O'Keefe
a13b268adc