- Updated the WebSocket upgrade detection logic in `isWebSocketUpgrade` to improve header handling and added a fallback for the "Sec-WebSocket-Key" header. - Refactored the WebSocket proxy logic to use a new `newMihomoWSTunnel` function, enhancing the connection handling process. - Introduced comprehensive test cases in `TestIsWebSocketUpgrade` to validate various WebSocket upgrade scenarios, ensuring robust functionality. - Improved error handling and request building for WebSocket upgrades, ensuring secure and efficient communication.