feat: 双击播放队列中的歌曲（不清空队列）

- 新增 POST /api/player/:botId/play-at 端点，跳转到队列指定索引
- 使用 queue.playAt(index) + resolveAndPlay，保留队列完整
- Queue.vue 添加 @dblclick 处理，双击即播放对应歌曲
- 添加 store.playAtIndex() action

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/web/api/player.ts

@@ -142,6 +142,32 @@ export function createPlayerRouter(
     }
   });
 
+  // Jump to a specific index in the queue (without clearing it)
+  router.post("/:botId/play-at", async (req, res) => {
+    try {
+      const bot = (req as any).bot;
+      const { index } = req.body;
+      if (typeof index !== "number" || index < 0) {
+        res.status(400).json({ error: "index is required" });
+        return;
+      }
+      const queue = bot.getQueueManager();
+      const song = queue.playAt(index);
+      if (!song) {
+        res.status(400).json({ error: "Invalid queue index" });
+        return;
+      }
+      const ok = await bot.resolveAndPlay(song);
+      if (!ok) {
+        res.json({ message: `Cannot play: ${song.name}` });
+        return;
+      }
+      res.json({ message: `Now playing: ${song.name} - ${song.artist}` });
+    } catch (err) {
+      res.status(500).json({ error: (err as Error).message });
+    }
+  });
+
   router.post("/:botId/playlist", async (req, res) => {
     try {
       const bot = (req as any).bot;

web/src/components/Queue.vue

@@ -18,6 +18,7 @@
         :key="`${song.id}-${i}`"
         class="queue-item"
         :class="{ active: store.currentSong?.id === song.id }"
+        @dblclick="playAtIndex(i)"
       >
         <CoverArt :url="song.coverUrl" :size="32" :radius="4" />
         <div class="queue-song-info">
@@ -54,6 +55,11 @@ watch(() => props.open, (isOpen) => {
   if (isOpen) store.fetchQueue();
 });
 
+async function playAtIndex(index: number) {
+  await store.playAtIndex(index);
+  await store.fetchQueue();
+}
+
 async function removeSong(index: number) {
   if (!store.activeBotId) return;
   try {
@@ -130,6 +136,8 @@ async function removeSong(index: number) {
   padding: 8px;
   border-radius: var(--radius-sm);
   transition: background var(--transition-fast);
+  cursor: pointer;
+  user-select: none;
 
   &:hover {
     background: var(--hover-bg);

web/src/stores/player.ts

@@ -172,6 +172,13 @@ export const usePlayerStore = defineStore('player', {
       setTimeout(() => this.syncElapsed(), 500);
     },
 
+    async playAtIndex(index: number) {
+      if (!this.activeBotId) return;
+      await axios.post(`/api/player/${this.activeBotId}/play-at`, { index });
+      this.serverElapsed = 0;
+      this._syncAfterAction();
+    },
+
     async play(query: string, platform = 'netease') {
       if (!this.activeBotId) return;
       await axios.post(`/api/player/${this.activeBotId}/play`, { query, platform });