fix(loyalty): translate category names in transaction history

Category names in transaction tables now resolve to the current
page language instead of always showing English. Updated:
- category_service.validate_category_for_store: accepts lang param,
  uses get_translated_name()
- Store transactions list route: passes request.state.language
- Card detail transactions route: passes request.state.language
- card_service.get_customer_transactions_with_store_names: accepts
  lang param for storefront route

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

app/modules/loyalty/routes/api/store.py

@@ -639,6 +639,7 @@ def get_card_detail(
 
 @router.get("/transactions", response_model=TransactionListResponse)
 def list_store_transactions(
+    request: Request,
     skip: int = Query(0, ge=0),
     limit: int = Query(10, ge=1, le=100),
     current_user: User = Depends(get_current_store_api),
@@ -647,6 +648,7 @@ def list_store_transactions(
     """List recent transactions for this merchant's loyalty program."""
     store_id = current_user.token_store_id
     merchant_id = get_store_merchant_id(db, store_id)
+    lang = getattr(request.state, "language", "en") or "en"
 
     transactions, total = card_service.get_store_transactions(
         db, merchant_id, skip=skip, limit=limit
@@ -663,7 +665,7 @@ def list_store_transactions(
             names = []
             for cid in t.category_ids:
                 name = category_service.validate_category_for_store(
-                    db, cid, t.store_id or 0
+                    db, cid, t.store_id or 0, lang=lang
                 )
                 if name:
                     names.append(name)
@@ -727,6 +729,7 @@ def enroll_customer(
 
 @router.get("/cards/{card_id}/transactions", response_model=TransactionListResponse)
 def get_card_transactions(
+    request: Request,
     card_id: int = Path(..., gt=0),
     skip: int = Query(0, ge=0),
     limit: int = Query(50, ge=1, le=100),
@@ -735,6 +738,7 @@ def get_card_transactions(
 ):
     """Get transaction history for a card."""
     store_id = current_user.token_store_id
+    lang = getattr(request.state, "language", "en") or "en"
 
     # Verify card belongs to this merchant (raises LoyaltyCardNotFoundException if not found)
     card_service.lookup_card_for_store(db, store_id, card_id=card_id)
@@ -743,10 +747,23 @@ def get_card_transactions(
         db, card_id, skip=skip, limit=limit
     )
 
-    return TransactionListResponse(
-        transactions=[TransactionResponse.model_validate(t) for t in transactions],
-        total=total,
-    )
+    from app.modules.loyalty.services.category_service import category_service
+
+    tx_responses = []
+    for t in transactions:
+        tx = TransactionResponse.model_validate(t)
+        if t.category_ids and isinstance(t.category_ids, list):
+            names = []
+            for cid in t.category_ids:
+                name = category_service.validate_category_for_store(
+                    db, cid, t.store_id or 0, lang=lang
+                )
+                if name:
+                    names.append(name)
+            tx.category_names = names if names else None
+        tx_responses.append(tx)
+
+    return TransactionListResponse(transactions=tx_responses, total=total)
 
 
 # =============================================================================

app/modules/loyalty/services/card_service.py

@@ -807,6 +807,7 @@ class CardService:
         *,
         skip: int = 0,
         limit: int = 20,
+        lang: str = "en",
     ) -> tuple[list[dict], int]:
         """
         Get transaction history for a card with store names resolved.
@@ -853,7 +854,7 @@ class CardService:
                 names = []
                 for cid in tx.category_ids:
                     name = category_service.validate_category_for_store(
-                        db, cid, tx.store_id or 0
+                        db, cid, tx.store_id or 0, lang=lang
                     )
                     if name:
                         names.append(name)

app/modules/loyalty/services/category_service.py

@@ -138,11 +138,11 @@ class CategoryService:
         logger.info(f"Deleted category {category_id} from store {store_id}")
 
     def validate_category_for_store(
-        self, db: Session, category_id: int, store_id: int
+        self, db: Session, category_id: int, store_id: int, lang: str = "en"
     ) -> str | None:
         """Validate that a category belongs to the store.
 
-        Returns the category name if valid, None if not found.
+        Returns the translated category name if valid, None if not found.
         """
         category = (
             db.query(StoreTransactionCategory)
@@ -153,7 +153,9 @@ class CategoryService:
             )
             .first()
         )
-        return category.name if category else None
+        if not category:
+            return None
+        return category.get_translated_name(lang)
 
 
 # Singleton