Configurable browser-side ICE servers

[shendriik]

In some network configurations, a TURN allocation on the go2rtc side is not sufficient. The browser also needs its own relay candidate.

The current card creates RTCPeerConnection with only the hardcoded Google STUN server.

Observed behavior

• go2rtc successfully allocates a TURN relay candidate;
• the remote relay candidate appears in chrome://webrtc-internals;
• ICE remains in checking;
• no video is displayed.

When the same TURN server is added to the browser-side RTCPeerConnection, ICE transitions to connected and the video starts working.

Tested scenarios

• an external Wi-Fi network;
• a network where the direct local route to go2rtc is unavailable.

Would you accept a PR adding an optional ice_servers card setting?

The setting would use the standard RTCIceServer structure and the existing behavior would remain unchanged when it is omitted.

Example:

type: custom:webrtc-camera
url: doorbell

ice_servers:
  - urls:
      - stun:stun.l.google.com:19302

  - urls:
      - turn:turn.example.org:3478?transport=udp
    username: rtc
    credential: password