test(timeline): add Playwright e2e + RTM rows for event note (#844)

zeitstrahl-note.spec.ts seeds PERSONAL and HISTORICAL events with
descriptions via API and asserts the note appears in DOM (REQ-001, REQ-004).
RTM rows REQ-001–REQ-008 for #844 all marked Done.

Closes #844
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/e2e/zeitstrahl-note.spec.ts

@@ -0,0 +1,77 @@
+import { test, expect, type APIRequestContext } from '@playwright/test';
+
+/**
+ * Curator-note display on /zeitstrahl (#844) — validates that a description saved
+ * against a curated timeline event surfaces in the DOM under that event's title.
+ * Covers REQ-001 (description flows from backend) and REQ-004 (rendered below title).
+ */
+
+const stamp = () => new Date().toISOString().replace(/[^0-9]/g, '');
+
+async function createEvent(
+	request: APIRequestContext,
+	type: 'PERSONAL' | 'HISTORICAL',
+	title: string,
+	description: string
+): Promise<string> {
+	const res = await request.post('/api/timeline/events', {
+		data: {
+			title,
+			type,
+			eventDate: '1918-11-11',
+			precision: 'DAY',
+			description
+		}
+	});
+	if (!res.ok()) throw new Error(`create event failed: ${res.status()} ${await res.text()}`);
+	return (await res.json()).id as string;
+}
+
+async function deleteEvent(request: APIRequestContext, id: string): Promise<void> {
+	await request.delete(`/api/timeline/events/${id}`);
+}
+
+test.describe('Zeitstrahl event note (#844)', () => {
+	let personalEventId: string;
+	let historicalEventId: string;
+	const personalTitle = `E2E Persönlich ${stamp()}`;
+	const historicalTitle = `E2E Historisch ${stamp()}`;
+	const personalNote = 'Persönliche Notiz für diesen Moment.';
+	const historicalNote = 'Historischer Kontext für dieses Ereignis.';
+
+	test.beforeAll(async ({ request }) => {
+		personalEventId = await createEvent(request, 'PERSONAL', personalTitle, personalNote);
+		historicalEventId = await createEvent(request, 'HISTORICAL', historicalTitle, historicalNote);
+	});
+
+	test.afterAll(async ({ request }) => {
+		if (personalEventId) await deleteEvent(request, personalEventId);
+		if (historicalEventId) await deleteEvent(request, historicalEventId);
+	});
+
+	test('PERSONAL curated event note appears below its title on /zeitstrahl (REQ-001, REQ-004)', async ({
+		page
+	}) => {
+		await page.goto('/zeitstrahl');
+
+		const personalEntry = page.locator('li').filter({ hasText: personalTitle }).first();
+		await expect(personalEntry).toBeVisible({ timeout: 10000 });
+
+		const note = personalEntry.locator('[data-testid="event-note"]');
+		await expect(note).toBeVisible();
+		await expect(note).toContainText(personalNote);
+	});
+
+	test('HISTORICAL curated event note appears below its title on /zeitstrahl (REQ-001, REQ-004)', async ({
+		page
+	}) => {
+		await page.goto('/zeitstrahl');
+
+		const historicalEntry = page.locator('li').filter({ hasText: historicalTitle }).first();
+		await expect(historicalEntry).toBeVisible({ timeout: 10000 });
+
+		const note = historicalEntry.locator('[data-testid="event-note"]');
+		await expect(note).toBeVisible();
+		await expect(note).toContainText(historicalNote);
+	});
+});