fix(tests): resolve 10 failing browser-mode tests

- Import layout.css in test-setup so Tailwind utilities (text-xs,
  min-h-[44px]) apply in vitest-browser — fixes computed-style assertions
  for badge font-size and touch-target height
- radioGroupNav: write aria-checked directly on radio buttons on arrow-key
  navigation, not only via the optional onChangeFn callback
- DashboardNeedsMetadata spec: tighten footer-link matcher from /50/ to
  /Alle 50/ — avoids strict-mode collision with row link whose relative
  time text also contains "50" (uploadedAt is exactly 50 days ago today)
- geschichten/[id] page spec: add missing await on userEvent.click before
  confirmService.settle() in both delete tests
- TypeSelector spec: replace storyCard.focus() (not on vitest-browser
  Locator) with userEvent.click(); force-dispatch aria-disabled Weiter
  click via element.click() to bypass Playwright actionability check

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/shared/actions/radioGroupNav.ts

@@ -19,6 +19,7 @@ export function radioGroupNav(
 		const next = (current + delta + radios.length) % radios.length;
 
 		radios[next].focus();
+		radios.forEach((r, i) => r.setAttribute('aria-checked', i === next ? 'true' : 'false'));
 		onChangeFn?.(radios[next].getAttribute('value') ?? '');
 	}