fix: add GET /cards/lookup endpoint for loyalty terminal customer search

The terminal JS uses GET with a free-text ?q= parameter, but only a POST
endpoint existed with typed params (card_id, qr_code, card_number).

- Add search_card_for_store service method (tries card number then email)
- Add GET /cards/lookup route using the service method
- Extract _build_card_lookup_response helper to DRY up POST and GET endpoints

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -311,6 +311,73 @@ def list_cards(
     return CardListResponse(cards=card_responses, total=total)
 
 
+def _build_card_lookup_response(card, db=None) -> CardLookupResponse:
+    """Build a CardLookupResponse from a card object."""
+    from datetime import timedelta
+
+    program = card.program
+
+    can_stamp, _ = card.can_stamp(program.cooldown_minutes)
+    cooldown_ends = None
+    if not can_stamp and card.last_stamp_at:
+        cooldown_ends = card.last_stamp_at + timedelta(minutes=program.cooldown_minutes)
+
+    stamps_today = card_service.get_stamps_today(db, card.id) if db else 0
+
+    available_rewards = []
+    for reward in program.points_rewards or []:
+        if reward.get("is_active", True) and card.points_balance >= reward.get(
+            "points_required", 0
+        ):
+            available_rewards.append(reward)
+
+    return CardLookupResponse(
+        card_id=card.id,
+        card_number=card.card_number,
+        customer_id=card.customer_id,
+        customer_name=card.customer.full_name if card.customer else None,
+        customer_email=card.customer.email if card.customer else "",
+        merchant_id=card.merchant_id,
+        merchant_name=card.merchant.name if card.merchant else None,
+        stamp_count=card.stamp_count,
+        stamps_target=program.stamps_target,
+        stamps_until_reward=max(0, program.stamps_target - card.stamp_count),
+        points_balance=card.points_balance,
+        can_redeem_stamps=card.stamp_count >= program.stamps_target,
+        stamp_reward_description=program.stamps_reward_description,
+        available_rewards=available_rewards,
+        can_stamp=can_stamp,
+        cooldown_ends_at=cooldown_ends,
+        stamps_today=stamps_today,
+        max_daily_stamps=program.max_daily_stamps,
+        can_earn_more_stamps=stamps_today < program.max_daily_stamps,
+    )
+
+
+@store_router.get("/cards/lookup", response_model=CardLookupResponse)
+def search_card(
+    request: Request,
+    q: str = Query(..., description="Search by email, card number, or name"),
+    current_user: User = Depends(get_current_store_api),
+    db: Session = Depends(get_db),
+):
+    """
+    Search for a card by email, card number, or customer name.
+
+    Tries matching in order: card number, then customer email.
+    Card must belong to the same merchant as the store.
+    """
+    store_id = current_user.token_store_id
+
+    card = card_service.search_card_for_store(db, store_id, q)
+    if not card:
+        from app.modules.loyalty.exceptions import LoyaltyCardNotFoundException
+
+        raise LoyaltyCardNotFoundException(q)
+
+    return _build_card_lookup_response(card, db)
+
+
 @store_router.post("/cards/lookup", response_model=CardLookupResponse)
 def lookup_card(
     request: Request,
@@ -337,46 +404,7 @@ def lookup_card(
         card_number=card_number,
     )
 
-    program = card.program
-
-    # Check cooldown
-    can_stamp, _ = card.can_stamp(program.cooldown_minutes)
-    cooldown_ends = None
-    if not can_stamp and card.last_stamp_at:
-        from datetime import timedelta
-
-        cooldown_ends = card.last_stamp_at + timedelta(minutes=program.cooldown_minutes)
-
-    # Get stamps today
-    stamps_today = card_service.get_stamps_today(db, card.id)
-
-    # Get available points rewards
-    available_rewards = []
-    for reward in program.points_rewards or []:
-        if reward.get("is_active", True) and card.points_balance >= reward.get("points_required", 0):
-            available_rewards.append(reward)
-
-    return CardLookupResponse(
-        card_id=card.id,
-        card_number=card.card_number,
-        customer_id=card.customer_id,
-        customer_name=card.customer.full_name if card.customer else None,
-        customer_email=card.customer.email if card.customer else "",
-        merchant_id=card.merchant_id,
-        merchant_name=card.merchant.name if card.merchant else None,
-        stamp_count=card.stamp_count,
-        stamps_target=program.stamps_target,
-        stamps_until_reward=max(0, program.stamps_target - card.stamp_count),
-        points_balance=card.points_balance,
-        can_redeem_stamps=card.stamp_count >= program.stamps_target,
-        stamp_reward_description=program.stamps_reward_description,
-        available_rewards=available_rewards,
-        can_stamp=can_stamp,
-        cooldown_ends_at=cooldown_ends,
-        stamps_today=stamps_today,
-        max_daily_stamps=program.max_daily_stamps,
-        can_earn_more_stamps=stamps_today < program.max_daily_stamps,
-    )
+    return _build_card_lookup_response(card, db)
 
 
 @store_router.post("/cards/enroll", response_model=CardResponse, status_code=201)