修复生成确认与素材导出

补齐外部生成确认请求的 JSON Content-Type

本地屏蔽已确认终态任务避免轮询重复弹窗

单素材导出改为读取 Blob 后触发浏览器下载

序列帧导出按 frame objectKey 换签读取

src/services/external-generation/externalGenerationClient.test.ts

@@ -0,0 +1,35 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { requestJson } from '../apiClient';
+import { acknowledgeExternalGenerationTasks } from './externalGenerationClient';
+
+vi.mock('../apiClient', () => ({
+  BACKGROUND_AUTH_REQUEST_OPTIONS: {
+    skipAuth: false,
+  },
+  requestJson: vi.fn(),
+}));
+
+const requestJsonMock = vi.mocked(requestJson);
+
+describe('externalGenerationClient', () => {
+  beforeEach(() => {
+    requestJsonMock.mockReset();
+    requestJsonMock.mockResolvedValue({ acknowledgedTasks: [] });
+  });
+
+  it('posts acknowledge requests as JSON', async () => {
+    await acknowledgeExternalGenerationTasks({ jobIds: ['job-1'] });
+
+    expect(requestJsonMock).toHaveBeenCalledWith(
+      '/api/runtime/external-generation/jobs/acknowledge',
+      expect.objectContaining({
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ jobIds: ['job-1'] }),
+      }),
+      '确认生成任务通知失败',
+      expect.any(Object),
+    );
+  });
+});