Establish a WebSocket connection for TCP proxy data transfer. This endpoint requires a valid session token obtained from POST /v1/tcp-proxy.

Token Properties:

• Single-use: token is invalidated upon WebSocket connection
• Short-lived: expires after 30 seconds if not used
• No authentication header needed: token in path serves as authorization

WebSocket Protocol:

• Binary frames (opcode 0x02) are used for data transfer in both directions
• Text frames (opcode 0x01) are used for control messages (JSON format)
• Close frame (opcode 0x08) terminates the connection

Control Messages (JSON):

• Connection ready: TcpProxyConnectedMessage, e.g. {"type": "connected", "channelId": 12345}
• Close notification: TcpProxyCloseMessage, e.g. {"type": "close", "reason": "normal"}