Refactor user endpoint tests to include pagination and response structure validation

- Updated tests for listing users to validate pagination and response format.
- Changed mock return values to include total count and pagination details.
- Refactored user creation mocks for clarity and consistency.
- Enhanced assertions to check for presence of pagination fields in responses.
- Adjusted test cases for user retrieval and updates to ensure proper handling of user data.
- Improved readability by restructuring mock definitions and assertions across various test files.

tests/services/test_credit.py

@@ -409,7 +409,9 @@ class TestCreditService:
 
     @pytest.mark.asyncio
     async def test_recharge_user_credits_success(
-        self, credit_service, sample_user,
+        self,
+        credit_service,
+        sample_user,
     ) -> None:
         """Test successful credit recharge for a user."""
         mock_session = credit_service.db_session_factory()