emit disconnected event and throw on dial error

[DTCurrie]

This PR resolves an issue where the RobotClient.dial method silently swallowed connection errors, making it impossible for developers to detect or handle connection failures.

Previously, if both WebRTC and subsequent gRPC connection attempts failed, the dial method would catch the exceptions, log them to the console, and return this as if the connection were successful.

The method now properly handles connection failures in two ways. For each failed connection attempt (WebRTC or gRPC), a DISCONNECTED event is emitted with the specific error, allowing developers to observe failures through the event system. When both WebRTC and gRPC connection methods fail, the method throws an Error with the message "Failed to connect via all methods". The thrown error includes both original errors in its cause property as an array, providing full context about why the connection failed.