fix(audio,sessions): unify audio playback state and improve session discovery

- move voice/audio players to single global audio engine with shared volume

- stop/reset previous track when switching to another media

- keep playback alive across chat switches via global audio element

- list refresh sessions by redis scan fallback when user session set is missing

web/src/components/MessageList.tsx

@@ -956,88 +956,43 @@ async function downloadFileFromUrl(url: string): Promise<void> {
 }
 
 function AudioInlinePlayer({ src, title }: { src: string; title: string }) {
-  const audioRef = useRef<HTMLAudioElement | null>(null);
-  const activate = useAudioPlayerStore((s) => s.activate);
-  const detach = useAudioPlayerStore((s) => s.detach);
-  const setPlayingState = useAudioPlayerStore((s) => s.setPlaying);
-  const setVolumeState = useAudioPlayerStore((s) => s.setVolume);
-  const [isPlaying, setIsPlaying] = useState(false);
-  const [duration, setDuration] = useState(0);
-  const [position, setPosition] = useState(0);
-  const [volume, setVolume] = useState(1);
+  const track = useAudioPlayerStore((s) => s.track);
+  const isPlayingGlobal = useAudioPlayerStore((s) => s.isPlaying);
+  const durationGlobal = useAudioPlayerStore((s) => s.duration);
+  const positionGlobal = useAudioPlayerStore((s) => s.position);
+  const volumeGlobal = useAudioPlayerStore((s) => s.volume);
+  const playTrack = useAudioPlayerStore((s) => s.playTrack);
+  const togglePlayGlobal = useAudioPlayerStore((s) => s.togglePlay);
+  const seekToGlobal = useAudioPlayerStore((s) => s.seekTo);
+  const setVolumeGlobal = useAudioPlayerStore((s) => s.setVolume);
 
-  useEffect(() => {
-    const audio = audioRef.current;
-    if (!audio) return;
-
-    const onLoaded = () => {
-      setDuration(Number.isFinite(audio.duration) ? audio.duration : 0);
-    };
-    const onTime = () => {
-      setPosition(audio.currentTime || 0);
-    };
-    const onEnded = () => {
-      setIsPlaying(false);
-      setPlayingState(audio, false);
-    };
-    const onPlay = () => {
-      activate(audio, { src, title });
-      setPlayingState(audio, true);
-    };
-    const onPause = () => {
-      setPlayingState(audio, false);
-    };
-
-    audio.addEventListener("loadedmetadata", onLoaded);
-    audio.addEventListener("timeupdate", onTime);
-    audio.addEventListener("ended", onEnded);
-    audio.addEventListener("play", onPlay);
-    audio.addEventListener("pause", onPause);
-    return () => {
-      audio.removeEventListener("loadedmetadata", onLoaded);
-      audio.removeEventListener("timeupdate", onTime);
-      audio.removeEventListener("ended", onEnded);
-      audio.removeEventListener("play", onPlay);
-      audio.removeEventListener("pause", onPause);
-      detach(audio);
-    };
-  }, [activate, detach, setPlayingState, src, title]);
+  const isActiveTrack = track?.src === src;
+  const isPlaying = isActiveTrack && isPlayingGlobal;
+  const duration = isActiveTrack ? durationGlobal : 0;
+  const position = isActiveTrack ? positionGlobal : 0;
+  const volume = volumeGlobal;
 
   async function togglePlay() {
-    const audio = audioRef.current;
-    if (!audio) return;
-    if (isPlaying) {
-      audio.pause();
-      setIsPlaying(false);
+    if (isActiveTrack) {
+      await togglePlayGlobal();
       return;
     }
-    try {
-      activate(audio, { src, title });
-      await audio.play();
-      setIsPlaying(true);
-    } catch {
-      setIsPlaying(false);
-    }
+    await playTrack({ src, title });
   }
 
   function onSeek(nextValue: number) {
-    const audio = audioRef.current;
-    if (!audio) return;
-    audio.currentTime = nextValue;
-    setPosition(nextValue);
+    if (!isActiveTrack) {
+      return;
+    }
+    seekToGlobal(nextValue);
   }
 
   function onVolume(nextValue: number) {
-    const audio = audioRef.current;
-    if (!audio) return;
-    audio.volume = nextValue;
-    setVolume(nextValue);
-    setVolumeState(audio, nextValue);
+    setVolumeGlobal(nextValue);
   }
 
   return (
     <div className="rounded-lg border border-sky-500/40 bg-sky-600/20 px-2 py-1.5">
-      <audio ref={audioRef} preload="metadata" src={src} />
       <div className="flex items-center gap-2">
         <button
           className="inline-flex h-7 w-7 items-center justify-center rounded-full bg-slate-900/70 text-xs text-white hover:bg-slate-900"