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/definition.py

@@ -60,7 +60,7 @@ def _get_feature_provider():
 
 def _get_onboarding_provider():
     """Lazy import of onboarding provider to avoid circular imports."""
-    from app.modules.loyalty.services.loyalty_onboarding import (
+    from app.modules.loyalty.services.loyalty_onboarding_service import (
         loyalty_onboarding_provider,
     )