The shared card-detail-view template already renders
card.customer_phone and card.customer_birthday, but CardDetailResponse
was missing both fields, so every consumer (admin, store, merchant)
silently returned them as undefined and the UI showed "-".
Added the two fields to the schema and populated them from
customer.phone / customer.birth_date in all three endpoints. Data was
persisting correctly all along — purely a serialization gap.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>