feat(backend): Update models and endpoints configuration

- Enhanced ticket and comment models with proper relationships
- Updated client_profile model for better data handling
- Improved auth endpoint with better error handling
- Updated main app configuration and imports
- Added new dependencies to requirements.txt
- Enhanced tickets endpoint with attachment support

backend/requirements.txt

@@ -69,6 +69,7 @@ prometheus-client==0.19.0
 pytest==7.4.3
 pytest-asyncio==0.21.1
 pytest-cov==4.1.0
+aiosqlite==0.19.0
 httpx==0.25.2            # For testing
 faker==20.1.0            # Test data generation