feat(moq-rtc): add WebRTC (WHIP/WHEP) gateway

Port the moq-rtc gateway from the dev branch. It bridges WebRTC and MoQ,
speaking WHIP (publish) and WHEP (subscribe) in either HTTP role, so it can
accept incoming peers (OBS, browsers) or dial out to a remote WebRTC server.
All four paths work; ingest covers H.264/VP8/VP9/Opus and egress adds
H.265/AV1, using str0m for ICE/DTLS/SRTP and a shared single-UDP-port mux.

Adapted to main's current APIs: `Broadcast`/`Track` model, infallible
`OriginConsumer::request_broadcast` + `OriginProducer::dynamic` (#1913),
`BroadcastConsumer::subscribe_track`, `publish_broadcast` lifetime tied to the
producer, moq-mux's in-place H.264 `Import` (avc3 mode), and moq-native's
`with_publish`/`with_consume` client builder.

Wires the crate into the workspace and documents it (doc/bin/rtc.md, index,
sidebar, crate map).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: kixelated

Cargo.lock

@@ -17,6 +17,7 @@ members = [
     "rs/moq-native",
     "rs/moq-net",
     "rs/moq-relay",
+    "rs/moq-rtc",
     "rs/moq-rtmp",
     "rs/moq-token",
     "rs/moq-token-cli",
@@ -40,6 +41,7 @@ default-members = [
     "rs/moq-mux",
     "rs/moq-native",
     "rs/moq-relay",
+    "rs/moq-rtc",
     "rs/moq-rtmp",
     "rs/moq-token",
     "rs/moq-token-cli",

Cargo.toml

@@ -137,6 +137,7 @@ export default defineConfig({
 							],
 						},
 						{ text: "CLI", link: "/bin/cli" },
+						{ text: "WebRTC", link: "/bin/rtc" },
 						{ text: "RTMP", link: "/bin/rtmp" },
 						{ text: "OBS", link: "/bin/obs" },
 						{ text: "GStreamer", link: "/bin/gstreamer" },

doc/.vitepress/config.ts

@@ -29,6 +29,12 @@ Another tool does the encoding (ex. ffmpeg), making it easy to pipe any media in
 ffmpeg -f avfoundation -i "0" -f mpegts - | moq-cli publish --url https://relay.example.com/anon --broadcast my-stream ts
 ```
 
+## [moq-rtc](/bin/rtc)
+
+A WebRTC <-> MoQ gateway. Speaks WHIP (publish) and WHEP (subscribe) in either
+HTTP role, so it can accept incoming peers (OBS, browsers) or dial out to a
+remote WebRTC server. Ingest and egress both work for H.264, VP8, VP9, and Opus.
+
 ## [moq-rtmp](/bin/rtmp)
 
 An RTMP / enhanced-RTMP -> MoQ ingest gateway. Accepts RTMP from any encoder