optimize register error tip

src/components/__tests__/App.test.tsx

@@ -1,7 +1,8 @@
-import { fireEvent, render, screen } from '@testing-library/react';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 
 import App from '../../App';
+import { uploadService } from '../../lib/uploadService';
 
 const { useAuthMock } = vi.hoisted(() => ({
   useAuthMock: vi.fn(),
@@ -57,7 +58,7 @@ vi.mock('../../components/LeftSidebar', () => ({
 }));
 
 vi.mock('../../components/FilePreview', () => ({
-  default: () => <div>preview</div>,
+  default: ({ file }: { file: { id: string } | null }) => <div>{file ? `preview:${file.id}` : 'preview-empty'}</div>,
 }));
 
 vi.mock('../../components/ResultPanel', () => ({
@@ -110,3 +111,48 @@ describe('App anonymous usage limit', () => {
     expect(screen.queryByText('upload-modal')).not.toBeInTheDocument();
   });
 });
+
+describe('App initial selection', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    localStorage.clear();
+    localStorage.setItem('hasSeenGuide', 'true');
+  });
+
+  it('does not auto-select the first history record on initial load', async () => {
+    useAuthMock.mockReturnValue({
+      user: { id: 'u1' },
+      initializing: false,
+    });
+
+    vi.mocked(uploadService.getTaskList).mockResolvedValue({
+      total: 1,
+      task_list: [
+        {
+          task_id: 'task-1',
+          file_name: 'sample.png',
+          status: 2,
+          origin_url: 'https://example.com/sample.png',
+          task_type: 'FORMULA',
+          created_at: '2026-03-06T00:00:00Z',
+          latex: '',
+          markdown: 'content',
+          mathml: '',
+          mml: '',
+          image_blob: '',
+          docx_url: '',
+          pdf_url: '',
+        },
+      ],
+    });
+
+    render(<App />);
+
+    await waitFor(() => {
+      expect(uploadService.getTaskList).toHaveBeenCalled();
+    });
+
+    expect(screen.getByText('preview-empty')).toBeInTheDocument();
+    expect(screen.queryByText('preview:task-1')).not.toBeInTheDocument();
+  });
+});