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.

app/core/config.py

@@ -20,7 +20,7 @@ class Settings(BaseSettings):
 
     # Production URLs (for reverse proxy deployment)
     FRONTEND_URL: str = "http://localhost:8001"  # Frontend URL in production
-    BACKEND_URL: str = "http://localhost:8000"   # Backend base URL
+    BACKEND_URL: str = "http://localhost:8000"  # Backend base URL
 
     # CORS Configuration
     CORS_ORIGINS: list[str] = ["http://localhost:8001"]  # Allowed origins for CORS