Count "Download from my account" as a backup for the Home nudge

Only "Download backup" recorded the date, so downloading from the account left
Home saying "You haven't downloaded a backup yet". Both now record it.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/settings/DataSection.jsx

@@ -81,7 +81,7 @@ export default function DataSection() {
       <div className="flex flex-wrap items-center gap-3">
         <button type="button" onClick={download} className={btn}>Download backup</button>
         {authUser && (
-          <a href="/api/account/export" download className={`${btn} inline-block`} title="Everything saved to your account on the server, including studies from other devices">Download from my account</a>
+          <a href="/api/account/export" download onClick={() => markBackedUp()} className={`${btn} inline-block`} title="Everything saved to your account on the server, including studies from other devices">Download from my account</a>
         )}
         <button type="button" onClick={() => fileRef.current?.click()} className={btn}>Restore from a backup…</button>
         <input ref={fileRef} type="file" accept="application/json,.json" onChange={choose} className="hidden" aria-label="Backup file" />

src/components/settings/DataSection.test.jsx

@@ -0,0 +1,37 @@
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { vi, test, expect, beforeEach } from 'vitest';
+import { AppContext } from '../../context/AppContext.js';
+import { ToastProvider } from '../Toasts.jsx';
+import { lastBackupAt } from '../../utils/backup.js';
+import DataSection from './DataSection.jsx';
+
+const value = {
+  authUser: { email: 'a@b.test' }, readerBookmarks: {}, readerBookmarkNotes: {}, readerTextHighlights: [], readerColorLabels: {}, readerInkByPage: {},
+  readingPlansState: { progress: [], customPlans: [], activity: [] }, importReaderMarks: vi.fn(), importReadingPlans: vi.fn(), refreshProjectIndex: vi.fn(), prayers: [], importPrayers: vi.fn(),
+};
+const setup = () => {
+  render(<AppContext.Provider value={value}><ToastProvider><DataSection /></ToastProvider></AppContext.Provider>);
+  return userEvent.setup();
+};
+
+beforeEach(() => {
+  localStorage.clear();
+  URL.createObjectURL = vi.fn(() => 'blob:x');
+  URL.revokeObjectURL = vi.fn();
+  document.addEventListener('click', (e) => { if (e.target.closest?.('a[download]')) e.preventDefault(); }); // no real navigation in the test
+});
+
+test('downloading the backup file is remembered, so Home stops asking', async () => {
+  const user = setup();
+  expect(lastBackupAt()).toBeNull();
+  await user.click(screen.getByRole('button', { name: 'Download backup' }));
+  expect(lastBackupAt()).toBeGreaterThan(Date.now() - 5000);
+});
+
+test('downloading from the account is remembered too', async () => {
+  const user = setup();
+  expect(lastBackupAt()).toBeNull();
+  await user.click(screen.getByRole('link', { name: 'Download from my account' }));
+  expect(lastBackupAt()).toBeGreaterThan(Date.now() - 5000);
+});