feat: P1 features — voice speed, private receipts, room filter, favorites, invite link, poll creation

P1-5: Voice message playback speed toggle (0.75×/1×/1.5×/2×) in AudioContent.tsx
P1-10: Private read receipts toggle in Privacy settings; wired to notifications.ts
P1-3: Room filter input on Home tab and DMs tab (client-side, clears on tab switch)
P1-8: Favorite rooms via m.favourite tag — Favorites section in Home sidebar, star/unstar in right-click menu
P1-9: Room invite link + QR code in room settings (Share Room tile, api.qrserver.com QR)
P1-6: Poll creation modal in composer (PollCreator.tsx, sends m.poll.start)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/components/message/content/AudioContent.tsx

@@ -96,6 +96,22 @@ export function AudioContent({
     useThrottle(handlePlayTimeCallback, PLAY_TIME_THROTTLE_OPS),
   );
 
+  const [playbackSpeed, setPlaybackSpeed] = useState<0.75 | 1 | 1.5 | 2>(1);
+
+  useEffect(() => {
+    if (audioRef.current) {
+      audioRef.current.playbackRate = playbackSpeed;
+    }
+  }, [playbackSpeed]);
+
+  const SPEED_STEPS: Array<0.75 | 1 | 1.5 | 2> = [0.75, 1, 1.5, 2];
+
+  const handleSpeedClick = () => {
+    const currentIndex = SPEED_STEPS.indexOf(playbackSpeed);
+    const nextIndex = (currentIndex + 1) % SPEED_STEPS.length;
+    setPlaybackSpeed(SPEED_STEPS[nextIndex]);
+  };
+
   const handlePlay = () => {
     if (srcState.status === AsyncStatus.Success) {
       setPlaying(!playing);
@@ -163,6 +179,15 @@ export function AudioContent({
         <Text size="T200">{`${secondsToMinutesAndSeconds(
           currentTime,
         )} / ${secondsToMinutesAndSeconds(duration)}`}</Text>
+
+        <Chip
+          onClick={handleSpeedClick}
+          variant="SurfaceVariant"
+          radii="Pill"
+          aria-label={`Playback speed: ${playbackSpeed}×`}
+        >
+          <Text size="B300">{`${playbackSpeed}×`}</Text>
+        </Chip>
       </>
     ),
     rightControl: (