Settings and the shortcuts list close from the corner

Both have nothing to confirm, so their only button was a lone X at the
foot of the card, below the fold of a long Settings card. A dialog with a
confirm keeps Cancel beside it at the bottom, where the pair belongs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/ui/app.spec.js

@@ -576,7 +576,7 @@ test('a second person has their own feeds and their own read state', async ({ br
   await page.locator('#prefs').click();
   await expect(page.locator('#modalCard')).toContainText('Subscriptions');
   await expect(page.locator('#modalCard')).toContainText('Only an admin changes this');
-  await page.locator('#modalCard .cardacts .btn').first().click();
+  await page.locator('#modalCard .cardx').click();
   await expect(page.locator('#admin')).toHaveCount(0);
   expect(await (await page.request.get('/')).text()).not.toContain('href=/admin');
   // Asking for it anyway goes back to the app, and its script is refused.