Reconnect: on "partner left", tear down the stale peer connection but stay in
the room, and have whichever peer is already present send the offer when the
other (re)joins — so a partner can leave and rejoin with no refresh, regardless
of who left. Every (re)negotiation runs on a fresh RTCPeerConnection.
Path indicator now reads the transport's selected candidate pair and prints the
actual local/remote IP:port + types, so DIRECT vs RELAYED is verifiable (host =
the two devices' IPs; relay = the TURN server's IP). The mic un-masks the real
host candidate, which is why a voice call reaches direct P2P on a LAN where the
no-mic chat fell back to TURN.
Russell Ballestrini
8dfdd9561c