Add support for Xfyun ASR and TTS services in the backend

- Introduce new Xfyun ASR and TTS services, enabling integration with iFlytek's voice recognition and synthesis capabilities.
- Update AssistantConfig model to include interface types for STT and TTS.
- Enhance credential testing to validate Xfyun credentials.
- Modify service factory to create Xfyun services based on configuration.
- Update README with new configuration details for Xfyun integration.
- Add new frontend components for visualizing audio streams and managing user interactions.

.claude/launch.json

@@ -9,6 +9,14 @@
       "port": 3001,
       "autoPort": false
     },
+    {
+      "name": "ai-video-admin-3000",
+      "runtimeExecutable": "npm",
+      "runtimeArgs": ["run", "dev"],
+      "cwd": "frontend",
+      "port": 3000,
+      "autoPort": false
+    },
     {
       "name": "ui-docker",
       "runtimeExecutable": "docker",