fix(loyalty): replace broad exception handlers with specific types and rename onboarding service

- Replace `except Exception` with specific exception types in
  google_wallet_service.py (requests.RequestException, ValueError, etc.)
  and apple_wallet_service.py (httpx.HTTPError, OSError, ssl.SSLError)
- Rename loyalty_onboarding.py -> loyalty_onboarding_service.py to
  match NAM-002 naming convention (+ test file + imports)
- Add PasswordChangeResponse Pydantic model to user_account API,
  removing raw dict return and noqa suppression

Resolves 12 EXC-003 + 1 NAM-002 architecture warnings in loyalty module.

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

app/modules/loyalty/tests/unit/test_loyalty_onboarding_service.py

@@ -1,4 +1,4 @@
-# app/modules/loyalty/tests/unit/test_loyalty_onboarding.py
+# app/modules/loyalty/tests/unit/test_loyalty_onboarding_service.py
 """Unit tests for LoyaltyOnboardingProvider."""
 
 import uuid
@@ -6,7 +6,9 @@ import uuid
 import pytest
 
 from app.modules.loyalty.models.loyalty_program import LoyaltyProgram, LoyaltyType
-from app.modules.loyalty.services.loyalty_onboarding import LoyaltyOnboardingProvider
+from app.modules.loyalty.services.loyalty_onboarding_service import (
+    LoyaltyOnboardingProvider,
+)
 from app.modules.tenancy.models import Merchant, Store, User