Implement microphone selection feature in voice preview

- Add audio input selection to DebugVoicePanel, allowing users to choose their microphone device.
- Update useVoicePreview hook to manage available audio inputs and selected device state.
- Enhance device enumeration and selection handling to ensure a seamless user experience during voice interactions.

frontend/src/components/pages/AssistantPage.tsx

@@ -1857,6 +1857,9 @@ function DebugVoicePanel({
     micWarning,
     localStream,
     messages,
+    audioInputs,
+    selectedDeviceId,
+    setSelectedDeviceId,
     sendText,
     connect,
     disconnect,
@@ -1942,6 +1945,33 @@ function DebugVoicePanel({
             </p>
           </div>
 
+          <div className="relative w-full max-w-xs">
+            <Select
+              value={selectedDeviceId || "default"}
+              onValueChange={(value) =>
+                setSelectedDeviceId(value === "default" ? "" : value)
+              }
+              disabled={recording}
+            >
+              <SelectTrigger
+                size="sm"
+                className="w-full justify-center gap-2 rounded-full border-hairline bg-canvas-soft text-xs text-muted-foreground"
+                aria-label="选择麦克风"
+              >
+                <Mic size={13} className="shrink-0 text-muted-soft" />
+                <SelectValue placeholder="默认麦克风" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="default">默认麦克风</SelectItem>
+                {audioInputs.map((device, index) => (
+                  <SelectItem key={device.deviceId} value={device.deviceId}>
+                    {device.label || `麦克风 ${index + 1}`}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
+
           <Button
             disabled={!assistantId || status === "connecting"}
             onClick={() => {