Add enableClientWellKnownLookups

Gate client well-known lookups on enableClientWellKnownLookups

New URL param (default on), threaded from the embedder. When off, always
avoid client .well-known: skip the post-login poll (widget + SPA) and the
legacy MatrixRTC foci fallback. When on/unset, respect the transports
endpoint response: only fall back to .well-known on a 404 M_UNRECOGNIZED.

src/state/CallViewModel/localMember/LocalTransport.ts

@@ -44,6 +44,7 @@ import {
 } from "../../../livekit/openIDSFU.ts";
 import { areLivekitTransportsEqual } from "../remoteMembers/MatrixLivekitMembers.ts";
 import { customLivekitUrl } from "../../../settings/settings.ts";
+import { getUrlParams } from "../../../UrlParams.ts";
 import { RtcTransportAutoDiscovery } from "./RtcTransportAutoDiscovery.ts";
 
 const logger = rootLogger.getChild("[LocalTransport]");
@@ -147,6 +148,7 @@ export const createLocalTransport$ = ({
   const transportDiscovery = new RtcTransportAutoDiscovery({
     client: client,
     resolvedConfig: Config.get(),
+    enableClientWellKnownLookups: getUrlParams().enableClientWellKnownLookups,
     wellKnownFetcher: AutoDiscovery.getRawClientConfig.bind(AutoDiscovery),
     logger: logger,
   });