Card detail has a focused add-card sheet

The card-detail action now opens a focused sheet containing the card identity, catalogue-supported printing choices, quantity, and an optional purchase price per card. Its primary action reflects the selected quantity.

Condition and language come from the selection already made on card detail, so the holding matches the displayed market without asking twice. The post-scan ownership form remains unchanged, and exact Masterset printing identities are preserved. The implementation is shared by iOS and Android.