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.

frontend/src/components/pages/ComponentsModelsPage.tsx

@@ -809,11 +809,18 @@ export function ComponentsModelsPage() {
                 htmlFor="model-api-key"
                 hint={{
                   description:
-                    "访问模型服务的鉴权密钥，由服务商控制台生成，请妥善保管勿泄露。",
-                  example: "sk-xxxxxxxx",
+                    form.interfaceType === "xfyun"
+                      ? "讯飞需要三段凭证，使用 JSON 存入现有 API Key 字段。"
+                      : "访问模型服务的鉴权密钥，由服务商控制台生成，请妥善保管勿泄露。",
+                  example:
+                    form.interfaceType === "xfyun"
+                      ? '{"appId":"...","apiKey":"...","apiSecret":"..."}'
+                      : "sk-xxxxxxxx",
                 }}
               >
-                API Key
+                {form.interfaceType === "xfyun"
+                  ? "Xfyun Credential JSON"
+                  : "API Key"}
               </FieldLabel>
               {hasStoredApiKey && (
                 <div className="mb-2 flex items-center gap-2 text-xs text-muted-foreground">
@@ -832,7 +839,9 @@ export function ComponentsModelsPage() {
                   placeholder={
                     hasStoredApiKey
                       ? "已配置，留空则保持不变"
-                      : "请输入 API Key"
+                      : form.interfaceType === "xfyun"
+                        ? '{"appId":"...","apiKey":"...","apiSecret":"..."}'
+                        : "请输入 API Key"
                   }
                   autoComplete="new-password"
                   className="border-hairline-strong bg-background pr-10 text-foreground placeholder:text-muted-soft"
@@ -852,6 +861,12 @@ export function ComponentsModelsPage() {
                   仅显示当前密钥首尾用于识别。留空可保持原密钥，输入新值将覆盖原密钥。
                 </p>
               )}
+              {form.interfaceType === "xfyun" && (
+                <p className="mt-2 text-xs leading-5 text-muted-foreground">
+                  ASR 的模型 ID 使用 iat；普通 TTS 使用 tts；超拟人 TTS 使用
+                  supertts。超拟人服务也可通过包含 /private/ 的 API URL 自动识别。
+                </p>
+              )}
             </div>
           </div>