A media-gateway server bridging a constrained watch (RTP/G.711) and a parent's app (WebRTC).
The watch is a microcontroller + cellular modem — it can't do WebRTC, so it's
emulated by a Node process, not a browser tab. Start it in a terminal:
node watch-emulator/watch.js
Then open the parent app above and call the watch. The server bridges the watch's
RTP/G.711 stream to the parent's WebRTC session: you'll hear the kid's voice
in the browser, and the watch saves your microphone audio to a WAV file.