fix(loyalty): card detail — enrolled store name + copy buttons

- Fix "Enrolled at: Unknown" by resolving enrolled_at_store_name from
  the store service and adding it to CardDetailResponse schema.
- Add clipboard-copy buttons next to card number, customer name,
  email, and phone fields using the shared Utils.copyToClipboard()
  utility with toast feedback.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/loyalty/schemas/card.py

@@ -100,6 +100,7 @@ class CardDetailResponse(CardResponse):
 
     # Merchant info
     merchant_name: str | None = None
+    enrolled_at_store_name: str | None = None
 
     # Program info
     program_name: str