test(e2e): fix locators, add print assertion, cleanup, remove redundant emulateMedia

- help-popover: replace broad button[aria-expanded] with specific
  getByLabel('Lese- und Bearbeitungsmodus'); update role="tooltip" →
  role="region"; add afterAll doc cleanup (Sara/Tobias)
- richtlinien: assert .new-tab spans are hidden in print media — the
  existing test only checked .app-nav (Sara)
- transcribe-coach: remove 4× redundant page.emulateMedia({reducedMotion})
  calls — playwright.config.ts already sets reducedMotion: 'reduce' globally;
  add afterAll doc cleanup (Tobias)

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

frontend/e2e/transcribe-coach.spec.ts

@@ -13,10 +13,13 @@ test.describe('Transcribe coach — empty state', () => {
 		docId = await createEmptyDocument(request);
 	});
 
+	test.afterAll(async ({ request }) => {
+		await request.delete(`/api/documents/${docId}`);
+	});
+
 	test('shows coach card (title, preamble, three step bodies, animation region)', async ({
 		page
 	}) => {
-		await page.emulateMedia({ reducedMotion: 'reduce' });
 		await page.goto(`/documents/${docId}`);
 		await page.getByRole('button', { name: 'Transkribieren' }).click();
 
@@ -31,14 +34,12 @@ test.describe('Transcribe coach — empty state', () => {
 	});
 
 	test('training footer is NOT visible on empty doc', async ({ page }) => {
-		await page.emulateMedia({ reducedMotion: 'reduce' });
 		await page.goto(`/documents/${docId}`);
 		await page.getByRole('button', { name: 'Transkribieren' }).click();
 		await expect(page.getByText('Für Training vormerken')).not.toBeVisible({ timeout: 3000 });
 	});
 
 	test('axe: panel empty state — light theme — no WCAG 2.1 AA violations', async ({ page }) => {
-		await page.emulateMedia({ reducedMotion: 'reduce' });
 		await page.goto(`/documents/${docId}`);
 		await page.getByRole('button', { name: 'Transkribieren' }).click();
 		await expect(page.getByRole('heading', { level: 2, name: /Erste Transkription/ })).toBeVisible({
@@ -50,7 +51,6 @@ test.describe('Transcribe coach — empty state', () => {
 	});
 
 	test('axe: panel empty state — dark theme — no WCAG 2.1 AA violations', async ({ page }) => {
-		await page.emulateMedia({ reducedMotion: 'reduce' });
 		await page.goto(`/documents/${docId}`);
 		// Toggle dark theme
 		await page.getByRole('button', { name: /Farbmodus|theme/i }).click();