fix: mute LivePlayer so live autoplay can start

Chrome/Edge block unmuted autoplay after async join;
silent play() failures left a black LIVE frame.

src/components/LivePlayer.vue

@@ -9,6 +9,7 @@
       ref="videoEl"
       controls
       autoplay
+      muted
       playsinline
     />
     <div v-else class="camera-scene">
@@ -92,14 +93,29 @@ async function attachPlayer(url) {
   const video = videoEl.value
   if (!video || seq !== attachSeq) return
 
+  video.muted = true
+  video.defaultMuted = true
+  video.setAttribute('muted', '')
+
   video.addEventListener('error', () => {
     if (seq !== attachSeq) return
     emit('error')
   }, { once: true })
 
+  async function tryPlay() {
+    if (seq !== attachSeq) return
+    try {
+      await video.play()
+    } catch (error) {
+      console.warn('[live-player] autoplay blocked', error)
+      // NotAllowedError: autoplay policy. Do not storm play-url rebuilds.
+      if (error?.name !== 'NotAllowedError' && seq === attachSeq) emit('error')
+    }
+  }
+
   if (video.canPlayType('application/vnd.apple.mpegurl')) {
     video.src = url
-    try { await video.play() } catch (_) {}
+    await tryPlay()
     return
   }
 
@@ -120,7 +136,8 @@ async function attachPlayer(url) {
     hls.attachMedia(video)
     hls.on(Hls.Events.MANIFEST_PARSED, () => {
       if (seq !== attachSeq) return
-      video.play().catch(() => {})
+      video.muted = true
+      tryPlay()
     })
   } catch (_) {
     if (seq === attachSeq) emit('error')