Implement WebRTC Bootstrap Server #2035
Description
Build the bootstrap server specified by #2033. This likely involves:
- Extracting/reusing P2P connection logic from the node
- HTTP endpoint for handling incoming signaling requests
- Supporting relay signaling to target peers via P2P channels
- Tracking relay-capable nodes (WebRTC Peer-Relay-Signaling Capability Discovery #2034)
- Health checks and metrics