fix: keep wait overlay alive for long waits

static/src/components/chat/monitor/MonitorDirector.ts

@@ -3761,22 +3761,31 @@ export class MonitorDirector implements MonitorDriver {
       clearInterval(this.waitOverlayTimer);
       this.waitOverlayTimer = null;
     }
+    let phase = 0;
     const update = () => {
       const elapsed = (performance.now() - start) / 1000;
-      const remain = Math.max(0, total - elapsed);
-      if (this.elements.waitCountdown) {
+      const remain = total - elapsed;
+      if (!this.elements.waitCountdown) {
+        return;
+      }
+      if (remain > 0) {
         this.elements.waitCountdown.textContent = this.formatWaitText(Math.ceil(remain));
+      } else {
+        const over = Math.ceil(-remain);
+        const dots = '.'.repeat(phase);
+        phase = (phase + 1) % 4;
+        this.elements.waitCountdown.textContent = `等待中 +${over}s${dots}`;
       }
     };
-    this.waitOverlayTimer = window.setInterval(update, 200);
+    this.waitOverlayTimer = window.setInterval(update, 260);
     const done = until || Promise.resolve();
+    const minDuration = new Promise(resolve => setTimeout(resolve, total * 1000));
     try {
-      await done;
-    } catch (_err) {
-      // 忽略错误，仍然结束动画
+      await Promise.all([done.catch(() => null), minDuration]);
+    } finally {
+      update();
+      this.hideWaitOverlay();
     }
-    update();
-    this.hideWaitOverlay();
   }
 
   /**