feat: wire Google Wallet into loyalty enrollment, stamps, and points flows

Connect the fully-implemented Google Wallet service to the loyalty module:
- Create wallet class/object on customer enrollment
- Sync wallet passes on stamp and points operations
- Expose wallet URLs in storefront API responses
- Add conditional "Add to Google Wallet" buttons on dashboard and enroll-success pages
- Use platform-wide env var config (not per-merchant DB column)
- Add Google service account patterns to .gitignore
- Add LOYALTY_GOOGLE_* fields to app Settings
- Update deployment docs and add local testing guide

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

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

@@ -24,7 +24,7 @@ from app.modules.loyalty.schemas import (
     CardResponse,
     ProgramResponse,
 )
-from app.modules.loyalty.services import card_service, program_service
+from app.modules.loyalty.services import card_service, program_service, wallet_service
 from app.modules.tenancy.exceptions import StoreNotFoundException
 
 storefront_router = APIRouter()
@@ -89,8 +89,32 @@ def self_enroll(
     logger.info(f"Self-enrollment for customer {customer_id} at store {store.subdomain}")
 
     card = card_service.enroll_customer_for_store(db, customer_id, store.id)
+    program = card.program
+    wallet_urls = wallet_service.get_add_to_wallet_urls(db, card)
 
-    return CardResponse.model_validate(card)
+    return {
+        "card": CardResponse(
+            id=card.id,
+            card_number=card.card_number,
+            customer_id=card.customer_id,
+            merchant_id=card.merchant_id,
+            program_id=card.program_id,
+            enrolled_at_store_id=card.enrolled_at_store_id,
+            stamp_count=card.stamp_count,
+            stamps_target=program.stamps_target,
+            stamps_until_reward=max(0, program.stamps_target - card.stamp_count),
+            total_stamps_earned=card.total_stamps_earned,
+            stamps_redeemed=card.stamps_redeemed,
+            points_balance=card.points_balance,
+            total_points_earned=card.total_points_earned,
+            points_redeemed=card.points_redeemed,
+            is_active=card.is_active,
+            created_at=card.created_at,
+            has_google_wallet=bool(card.google_object_id),
+            has_apple_wallet=bool(card.apple_serial_number),
+        ),
+        "wallet_urls": wallet_urls,
+    }
 
 
 # =============================================================================
@@ -137,10 +161,32 @@ def get_my_card(
     program_response.is_points_enabled = program.is_points_enabled
     program_response.display_name = program.display_name
 
+    wallet_urls = wallet_service.get_add_to_wallet_urls(db, card)
+
     return {
-        "card": CardResponse.model_validate(card),
+        "card": CardResponse(
+            id=card.id,
+            card_number=card.card_number,
+            customer_id=card.customer_id,
+            merchant_id=card.merchant_id,
+            program_id=card.program_id,
+            enrolled_at_store_id=card.enrolled_at_store_id,
+            stamp_count=card.stamp_count,
+            stamps_target=program.stamps_target,
+            stamps_until_reward=max(0, program.stamps_target - card.stamp_count),
+            total_stamps_earned=card.total_stamps_earned,
+            stamps_redeemed=card.stamps_redeemed,
+            points_balance=card.points_balance,
+            total_points_earned=card.total_points_earned,
+            points_redeemed=card.points_redeemed,
+            is_active=card.is_active,
+            created_at=card.created_at,
+            has_google_wallet=bool(card.google_object_id),
+            has_apple_wallet=bool(card.apple_serial_number),
+        ),
         "program": program_response,
         "locations": [{"id": v.id, "name": v.name} for v in locations],
+        "wallet_urls": wallet_urls,
     }