Reads a `webrtc://` offer from stdin, answers it, bridges ICE candidates
as JSON lines over stdin/stdout and echoes every message. rustdesk-web-js
drives it from Chrome (js/e2e/webrtc) to check that the browser transport
and WebRTCStream still agree on the envelope, the signed fingerprint, the
candidate JSON and the fragment framing.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JXJJGEGdgu26wgCppvUXdZ
