fix: isolate startup tools and preview dialogs

frontend/src/components/assistant-editor/debug-preview.tsx

@@ -645,6 +645,8 @@ function DebugVoicePanel({
   const recording = status === "connecting" || status === "connected";
   const [textDraft, setTextDraft] = useState("");
   const [inputMode, setInputMode] = useState<DebugInputMode>("mic");
+  const [clientDialogContainer, setClientDialogContainer] =
+    useState<HTMLDivElement | null>(null);
   const inChatView = view === "chat" && (!SHOW_VOICE_VIZ || showTranscript);
   const idleOrFailed = status === "idle" || status === "failed";
   const showIdleHub =
@@ -682,10 +684,17 @@ function DebugVoicePanel({
   ]);
 
   return (
-    <div className="flex min-h-0 flex-1 flex-col">
+    <div
+      ref={setClientDialogContainer}
+      className="relative isolate flex min-h-0 flex-1 flex-col overflow-hidden"
+    >
       {/* 后端 TTS 音频经 WebRTC 媒体流过来,挂这里播放 */}
       <audio ref={audioRef} autoPlay playsInline className="hidden" />
-      <ClientMessageDialog preview={preview} />
+      <ClientMessageDialog
+        preview={preview}
+        container={clientDialogContainer}
+        contained
+      />
       {vision && !showIdleHub ? (
         <DebugVisionWorkspace
           view={view}