Leave the page title to the page

The call and the lobby each set `document.title`, so a component
embedded in a host renamed the host's tab to "Element Call | <room>".
The title belongs to whoever owns the page: the standalone app's
RoomPage now sets it, for whichever room it has got as far as knowing
about, and the call itself no longer touches it.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/room/LobbyView.tsx

@@ -44,7 +44,6 @@ import {
   useTrackProcessor,
   useTrackProcessorSync,
 } from "../livekit/TrackProcessorContext";
-import { usePageTitle } from "../usePageTitle";
 import { getValue } from "../utils/observable";
 import { useBehavior } from "../useBehavior";
 import { CallFooter, type FooterSnapshot } from "../components/CallFooter";
@@ -87,7 +86,6 @@ export const LobbyView: FC<Props> = ({
 
   const { t } = useTranslation();
 
-  usePageTitle(matrixInfo.roomName);
   useAppBarPrimaryButtonIconKind("back");
   const audioEnabled = useBehavior(muteStates.audio.enabled$);
   const videoEnabled = useBehavior(muteStates.video.enabled$);