phsl / new-api

- Add comprehensive error handling for SSE events
- Implement proper error state UI with Semi Typography
- Prevent white screen issues on non-200 responses
- Add error logging for better debugging
- Enhance message state management for error conditions
- Improve user feedback with i18n error messages
- Ensure UI stability during error states
- Add try-catch blocks for JSON parsing and stream initialization
- Handle connection termination gracefully
- Preserve error states in message stream updates