- Add proxy field to ProviderEndpoint database model with migration
- Add ProxyConfig Pydantic model for proxy URL validation
- Extend HTTP client pool with create_client_with_proxy method
- Integrate proxy configuration in chat_handler_base.py and cli_handler_base.py
- Update admin API endpoints to support proxy configuration CRUD
- Add proxy configuration UI in frontend EndpointFormDialog
Fixes#28
- Enhance error classifier to properly handle API key failures with fallback support
- Add error reason/code parsing for better AWS and multi-provider compatibility
- Improve error message structure detection for non-standard formats
- Refactor file logging with size-based rotation (100MB) instead of daily
- Optimize production logging by disabling backtrace and diagnose
- Clean up model validation and remove redundant configurations