- Accept {type: 'message', content} format from nyx
- Handle 'new' (create fresh session), 'stop' (cancel pipeline)
- Ignore 'ping', 'auth', 'connect' (auth via query params)
- Send 'ready' after session_info on WS connect
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>