feat: expose localUfrag on IceUdpMuxRequest

Passes through `rtc::IceUdpMuxRequest::localUfrag` from libdatachannel to
the JS `onUnhandledStunRequest` callback. Needed by the libp2p
WebRTC-Direct v2 transport design (libp2p/specs#715).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: tabcat

src/cpp/ice-udp-mux-listener-wrapper.cpp

@@ -145,6 +145,7 @@ void IceUdpMuxListenerWrapper::onUnhandledStunRequest(const Napi::CallbackInfo &
           {
         Napi::Object reqObj = Napi::Object::New(env);
         reqObj.Set("ufrag", request.remoteUfrag.c_str());
+        reqObj.Set("localUfrag", request.localUfrag.c_str());
         reqObj.Set("host", request.remoteAddress.c_str());
         reqObj.Set("port", request.remotePort);
 

src/lib/types.ts

@@ -157,6 +157,7 @@ export type Direction = 'SendOnly' | 'RecvOnly' | 'SendRecv' | 'Inactive' | 'Unk
 
 export interface IceUdpMuxRequest {
   ufrag: string;
+  localUfrag: string;
   host: string;
   port: number;
 }