music(player): 加音量条 + 静音按钮（localStorage 持久化）

apps/music/frontend/src/views/PlayerView.vue

@@ -230,6 +230,20 @@
                 <div class="fill" :style="{ width: progressPct + '%' }"></div>
               </div>
               <span class="time">{{ fmtTime(duration) }}</span>
+              <button
+                class="btn-icon vol-icon"
+                :title="muted ? '取消静音' : '静音'"
+                @click="toggleMute"
+              >{{ volIcon }}</button>
+              <input
+                class="vol-slider"
+                type="range"
+                min="0"
+                max="100"
+                :value="muted ? 0 : Math.round(volume * 100)"
+                @input="onVolumeInput"
+                title="音量"
+              />
             </div>
           </footer>
 
@@ -336,6 +350,37 @@ const activeTagName = ref(null)
 const search = ref('')
 const sortMode = ref(localStorage.getItem('music.sort') || 'name')
 const repeatOne = ref(false)
+const volume = ref(parseFloat(localStorage.getItem('music.vol') || '1'))
+const muted = ref(localStorage.getItem('music.muted') === '1')
+
+const volIcon = computed(() => {
+  if (muted.value || volume.value === 0) return '🔇'
+  if (volume.value < 0.34) return '🔈'
+  if (volume.value < 0.67) return '🔉'
+  return '🔊'
+})
+
+function applyVolume() {
+  if (audioEl.value) {
+    audioEl.value.volume = volume.value
+    audioEl.value.muted = muted.value
+  }
+}
+
+function onVolumeInput(e) {
+  const v = parseInt(e.target.value, 10) / 100
+  volume.value = isNaN(v) ? 0 : Math.max(0, Math.min(1, v))
+  if (volume.value > 0 && muted.value) muted.value = false
+  localStorage.setItem('music.vol', String(volume.value))
+  localStorage.setItem('music.muted', muted.value ? '1' : '0')
+  applyVolume()
+}
+
+function toggleMute() {
+  muted.value = !muted.value
+  localStorage.setItem('music.muted', muted.value ? '1' : '0')
+  applyVolume()
+}
 
 const audioEl = ref(null)
 const lyricsBoxEl = ref(null)
@@ -650,6 +695,7 @@ function onTimeUpdate(e) {
 
 function onLoaded(e) {
   duration.value = e.target.duration || 0
+  applyVolume()
 }
 
 function onEnded() {
@@ -1364,6 +1410,38 @@ onBeforeUnmount(() => {
   text-align: center;
 }
 
+.vol-icon { font-size: 16px; width: 32px; height: 32px; }
+.vol-slider {
+  -webkit-appearance: none;
+  appearance: none;
+  width: 90px;
+  height: 4px;
+  background: var(--border);
+  border-radius: 2px;
+  cursor: pointer;
+}
+.vol-slider:focus { outline: none; }
+.vol-slider::-webkit-slider-thumb {
+  -webkit-appearance: none;
+  appearance: none;
+  width: 12px;
+  height: 12px;
+  background: var(--accent-strong);
+  border-radius: 50%;
+  cursor: pointer;
+}
+.vol-slider::-moz-range-thumb {
+  width: 12px;
+  height: 12px;
+  background: var(--accent-strong);
+  border: none;
+  border-radius: 50%;
+  cursor: pointer;
+}
+@media (max-width: 768px) {
+  .vol-slider { width: 60px; }
+}
+
 /* Chat sidebar */
 .chat {
   width: 320px;