fix frontend voice preview fallback

frontend/src/components/pages/AssistantPage.tsx

@@ -1790,9 +1790,15 @@ function DebugVoicePanel({
   vizStyle: VizStyle;
   assistantId: string | null;
 }) {
-  const [micError, setMicError] = useState(false);
-  const { status, error, localStream, connect, disconnect, audioRef } =
-    useVoicePreview(assistantId, { onMicError: () => setMicError(true) });
+  const {
+    status,
+    error,
+    micWarning,
+    localStream,
+    connect,
+    disconnect,
+    audioRef,
+  } = useVoicePreview(assistantId);
   // 连接中或已连通都视作"会话进行中"
   const recording = status === "connecting" || status === "connected";
 
@@ -1827,15 +1833,10 @@ function DebugVoicePanel({
 
           <div className="relative flex h-[200px] w-[240px] shrink-0 items-center justify-center">
             {(() => {
-              const onVizError = () => {
-                setMicError(true);
-                disconnect();
-              };
               const shared = {
                 active: Boolean(localStream),
                 stream: localStream,
                 className: "relative shrink-0",
-                onError: onVizError,
               } as const;
               if (vizStyle === "aura")
                 return <AuraVisualizer {...shared} size={200} />;
@@ -1852,17 +1853,19 @@ function DebugVoicePanel({
               {status === "connecting"
                 ? "连接中…"
                 : status === "connected"
-                  ? "我在聆听"
+                  ? micWarning
+                    ? "仅收听模式"
+                    : "我在聆听"
                   : "开始一次语音对话"}
             </div>
             <p className="mx-auto text-xs leading-5 text-muted-foreground">
-              {micError
-                ? "无法访问麦克风，请检查浏览器权限后重试。"
-                : status === "failed"
+              {status === "failed"
                   ? error ||
                     "连接失败，请确认后端已启动且助手已保存后重试。"
                   : !assistantId
                     ? "请先保存助手，再开始语音预览。"
+                    : micWarning
+                      ? `${micWarning} 可接收助手播报，但无法发送语音。`
                     : recording
                       ? "直接说话即可。助手会在您停顿后自然回应。"
                       : "测试语音识别、响应速度与助手的播报效果。"}
@@ -1872,7 +1875,6 @@ function DebugVoicePanel({
           <Button
             disabled={!assistantId || status === "connecting"}
             onClick={() => {
-              setMicError(false);
               if (recording) {
                 disconnect();
               } else {