fix(chat): guard activity poll against overlapping interval ticks

mateclaw-ui/src/views/ChatConsole.vue

@@ -1150,6 +1150,12 @@ function applyPendingRouteAction() {
 // 轮询定时器：让 ChatConsole 能实时感知外部渠道（WeChat/DingTalk/…）推进来的新消息，
 // 无需 F5 即可看到侧栏列表更新和选中会话的消息/流状态。
 let activityPollTimer: number | null = null
+// Reentrancy guard: setInterval fires every ACTIVITY_POLL_MS regardless of
+// whether the previous async pollActivity has finished. If one cycle runs long
+// (slow reconnectStream / sluggish backend), unguarded ticks stack up and run
+// concurrently, multiplying in-flight requests. This flag keeps one cycle at a
+// time — late ticks become no-ops until the running cycle returns.
+let activityPolling = false
 const ACTIVITY_POLL_MS = 4000
 
 // Cron progress placeholder: when a cron job is mid-run on the currently
@@ -1223,6 +1229,10 @@ function hasLocalOnlyFailedTail(): boolean {
 async function pollActivity() {
   // 页面不可见时不轮询，避免切到别的标签还在空耗
   if (typeof document !== 'undefined' && document.hidden) return
+  // Skip when the previous cycle is still running so slow polls can't stack.
+  if (activityPolling) return
+  activityPolling = true
+  try {
     try {
       await loadConversations()
     } catch {
@@ -1257,6 +1267,9 @@ async function pollActivity() {
       // runs use the non-streaming chat() path, so streamStatus stays idle.
       await refreshActiveCronRuns(cid)
     }
+  } finally {
+    activityPolling = false
+  }
 }
 
 onMounted(async () => {