fix: mitt v3 on() 返回 void，改用 off() 取消订阅

src/components/baseLayouts/Lobby.vue

@@ -89,26 +89,33 @@ watch(activeGameId, () => {
 /** 首次加载 */
 fetchRoomList()
 
-// ===== SSE 实时事件订阅 =====
-onMounted(() => {
-  const offs = [
-    // 新房间创建 → 添加到列表头部
-    sseBus.on('room_created', (room: RoomItem) => {
+// ===== SSE 实时事件订阅处理函数 =====
+/** 新房间创建 → 添加到列表头部 */
+function onRoomCreated(room: RoomItem) {
   rooms.value.unshift(room)
-    }),
-    // 房间状态更新 → 局部替换
-    sseBus.on('room_updated', (room: RoomItem) => {
+}
+/** 房间状态更新 → 局部替换 */
+function onRoomUpdated(room: RoomItem) {
   const idx = rooms.value.findIndex((r) => r.id === room.id)
   if (idx >= 0) {
     rooms.value[idx] = room
   }
-    }),
-    // 房间移除 → 从列表中删除
-    sseBus.on('room_removed', ({ roomId }: { roomId: string }) => {
+}
+/** 房间移除 → 从列表中删除 */
+function onRoomRemoved({ roomId }: { roomId: string }) {
   rooms.value = rooms.value.filter((r) => r.id !== roomId)
+}
+
+// ===== SSE 实时事件订阅 =====
+onMounted(() => {
+  sseBus.on('room_created', onRoomCreated)
+  sseBus.on('room_updated', onRoomUpdated)
+  sseBus.on('room_removed', onRoomRemoved)
 })
-  ]
-  onUnmounted(() => offs.forEach((fn) => fn()))
+onUnmounted(() => {
+  sseBus.off('room_created', onRoomCreated)
+  sseBus.off('room_updated', onRoomUpdated)
+  sseBus.off('room_removed', onRoomRemoved)
 })
 
 /** 筛选后的房间列表 */