feat: enhance WelcomeDialog, export dialogs, GitStatusPanel, add CommandPalette, FindReplaceBar, and new converter dialogs

- WelcomeDialog: add quick start, feature showcase, keyboard shortcuts, recent files, version display
- ExportDocxDialog/ExportHtmlDialog/ExportPdfDialog: add header/footer, paper size, margin controls
- GitStatusPanel: full staging/unstaging, discard, commit workflow
- CommandPalette: fuzzy command search with keyboard navigation
- FindReplaceBar: find/replace with regex, case, whole-word options
- New dialogs: BatchMediaConverterDialog, HeaderFooterDialog, PdfEditorDialog, UniversalConverterDialog
- Tests: comprehensive coverage for all new/updated components

tests/component/modals/ExportPdfDialog.test.tsx

@@ -17,28 +17,63 @@ vi.mock('@/lib/ipc', () => ({
 
 import { ipc } from '@/lib/ipc';
 
-describe('ExportPdfDialog', () => {
-  beforeEach(() => {
-    localStorage.clear();
-    vi.clearAllMocks();
-    useSettingsStore.setState(useSettingsStore.getInitialState());
-    useFileStore.setState({
-      activeTabId: '/test.md',
-      openTabs: [{ id: '/test.md', path: '/test.md', title: 'test.md', dirty: false }],
-    } as any);
-    useEditorStore.setState({
-      buffers: new Map([
-        ['/test.md', { id: '/test.md', path: '/test.md', content: '# hi', dirty: false }],
-      ]),
-    } as any);
-  });
+beforeEach(() => {
+  localStorage.clear();
+  vi.clearAllMocks();
+  delete (window as any).electronAPI;
+  useSettingsStore.setState(useSettingsStore.getInitialState());
+  useFileStore.setState({
+    activeTabId: '/test.md',
+    openTabs: [{ id: '/test.md', path: '/test.md', title: 'test.md', dirty: false }],
+  } as any);
+  useEditorStore.setState({
+    buffers: new Map([
+      ['/test.md', { id: '/test.md', path: '/test.md', content: '# hi', dirty: false }],
+    ]),
+  } as any);
+});
 
+describe('ExportPdfDialog', () => {
   it('renders with default PDF options from settings', () => {
     render(<ExportPdfDialog sourcePath="/test.md" />);
     expect(screen.getByText(/export to pdf/i)).toBeInTheDocument();
     expect(screen.getByRole('combobox', { name: /format/i })).toBeInTheDocument();
   });
 
+  it('shows PDF engine selector', () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    expect(screen.getByRole('combobox', { name: /pdf engine/i })).toBeInTheDocument();
+  });
+
+  it('shows TOC toggle and number sections toggle', () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    expect(screen.getByRole('switch', { name: /table of contents/i })).toBeInTheDocument();
+    expect(screen.getByRole('switch', { name: /number sections/i })).toBeInTheDocument();
+  });
+
+  it('shows TOC depth input when TOC is enabled', async () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    await userEvent.click(screen.getByRole('switch', { name: /table of contents/i }));
+    expect(screen.getByLabelText(/toc depth/i)).toBeInTheDocument();
+  });
+
+  it('shows page geometry dropdown', () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    expect(screen.getByRole('combobox', { name: /page geometry/i })).toBeInTheDocument();
+  });
+
+  it('shows bibliography and font inputs', () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    expect(screen.getByLabelText(/bibliography file path/i)).toBeInTheDocument();
+    expect(screen.getByLabelText(/main font/i)).toBeInTheDocument();
+    expect(screen.getByLabelText(/cjk font/i)).toBeInTheDocument();
+  });
+
+  it('shows highlight style selector', () => {
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    expect(screen.getByRole('combobox', { name: /highlight style/i })).toBeInTheDocument();
+  });
+
   it('toggles ASCII tables and submits via ipc.print.show', async () => {
     render(<ExportPdfDialog sourcePath="/test.md" />);
     await userEvent.click(screen.getByRole('checkbox', { name: /ascii/i }));
@@ -46,16 +81,30 @@ describe('ExportPdfDialog', () => {
     await waitFor(() => expect(ipc.print.show).toHaveBeenCalledTimes(1));
     const [arg] = (ipc.print.show as any).mock.calls[0];
     expect(arg.html).toContain('<!DOCTYPE html>');
-    // The Markdown source is rendered to HTML inside the document body.
     expect(arg.html).toContain('<h1>hi</h1>');
-    // @page CSS for size + margins must be present
     expect(arg.html).toMatch(/@page\s*\{\s*size:\s*210mm\s+297mm/);
   });
 
-  it('renders an error banner when IPC fails', async () => {
-    (ipc.print.show as any).mockRejectedValueOnce(new Error('Pandoc not found'));
+  it('uses electronAPI.export.withOptions when available', async () => {
+    const mockWithOptions = vi.fn().mockResolvedValue({ ok: true });
+    (window.electronAPI as any) = {
+      export: { withOptions: mockWithOptions },
+    };
     render(<ExportPdfDialog sourcePath="/test.md" />);
     await userEvent.click(screen.getByRole('button', { name: /^export$/i }));
-    expect(await screen.findByText(/pandoc not found/i)).toBeInTheDocument();
+    await waitFor(() => expect(mockWithOptions).toHaveBeenCalledWith('pdf', expect.any(Object)));
+    expect(mockWithOptions.mock.calls[0][1].engine).toBe('pdflatex');
+    expect(mockWithOptions.mock.calls[0][1].toc).toBe(false);
+    expect(mockWithOptions.mock.calls[0][1].highlightStyle).toBe('tango');
+  });
+
+  it('renders an error banner when IPC fails', async () => {
+    (window as any).electronAPI = undefined;
+    (ipc.print.show as any).mockReturnValueOnce({ ok: false, error: { message: 'Pandoc not found' } });
+    render(<ExportPdfDialog sourcePath="/test.md" />);
+    await userEvent.click(screen.getByRole('button', { name: /^export$/i }));
+    await waitFor(() => {
+      expect(screen.getByRole('alert')).toHaveTextContent(/pandoc not found/i);
+    });
   });
 });