fix(tests): fix Svelte 5 event delegation not firing via Playwright locator clicks

Replace Playwright locator .click() calls with native DOM element.click()
for all tests that trigger Svelte 5 delegated onclick handlers ($.delegated).
Playwright's CDP-based synthetic events don't propagate through Svelte 5's
document-level handle_event_propagation delegation mechanism, while native
DOM .click() does.

Also replace locator.click() with element.focus() for onfocus handler tests,
and add cleanup() to afterEach in all spec files missing it to prevent test
pollution between runs. Fix TagInput.svelte to use untrack() when reading
bindable state after an await to avoid track_reactivity_loss errors.

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

frontend/e2e/persons.spec.ts

@@ -211,3 +211,84 @@ test.describe('Conversations', () => {
 		await page.screenshot({ path: 'test-results/e2e/conversations-sort.png' });
 	});
 });
+
+test.describe('Conversations — enhancements', () => {
+	// Hans→Anna (1923) and Anna→Hans (1965) are seeded in DataInitializer
+	// Navigate directly by URL so the test doesn't rely on typeahead interaction
+	async function loadHansAnnaConversation(page: import('@playwright/test').Page) {
+		// Resolve person IDs from the persons list
+		await page.goto('/persons');
+		const hansLink = page.getByRole('link', { name: /Hans Müller/ }).first();
+		const hansHref = await hansLink.getAttribute('href');
+		const hansId = hansHref!.split('/').pop()!;
+
+		const annaLink = page.getByRole('link', { name: /Anna Schmidt/ }).first();
+		const annaHref = await annaLink.getAttribute('href');
+		const annaId = annaHref!.split('/').pop()!;
+
+		await page.goto(`/conversations?senderId=${hansId}&receiverId=${annaId}`);
+		await page.waitForURL(/senderId=/);
+	}
+
+	test('shows document count and year range summary when both persons are selected', async ({
+		page
+	}) => {
+		await loadHansAnnaConversation(page);
+		// Hans→Anna (1923) + Anna→Hans (1965) = 2 documents, range 1923–1965
+		await expect(page.getByTestId('conv-summary')).toContainText('2');
+		await expect(page.getByTestId('conv-summary')).toContainText('1923');
+		await expect(page.getByTestId('conv-summary')).toContainText('1965');
+		await page.screenshot({ path: 'test-results/e2e/conversations-summary.png' });
+	});
+
+	test('shows year dividers between documents from different years', async ({ page }) => {
+		await loadHansAnnaConversation(page);
+		// Expect at least two year dividers (1923 and 1965)
+		await expect(page.getByTestId('year-divider').first()).toBeVisible();
+		const dividers = page.getByTestId('year-divider');
+		const texts = await dividers.allTextContents();
+		expect(texts.some((t) => t.includes('1923'))).toBe(true);
+		expect(texts.some((t) => t.includes('1965'))).toBe(true);
+		await page.screenshot({ path: 'test-results/e2e/conversations-year-dividers.png' });
+	});
+
+	test('swap button switches sender and receiver and reloads', async ({ page }) => {
+		await loadHansAnnaConversation(page);
+		const url = new URL(page.url());
+		const originalSenderId = url.searchParams.get('senderId')!;
+		const originalReceiverId = url.searchParams.get('receiverId')!;
+
+		await page.getByTestId('conv-swap-btn').click();
+		await page.waitForURL(/senderId=/);
+
+		const swappedUrl = new URL(page.url());
+		expect(swappedUrl.searchParams.get('senderId')).toBe(originalReceiverId);
+		expect(swappedUrl.searchParams.get('receiverId')).toBe(originalSenderId);
+		await page.screenshot({ path: 'test-results/e2e/conversations-swap.png' });
+	});
+
+	test('shows "new document" link pre-filled with both persons when conversation is loaded', async ({
+		page
+	}) => {
+		await loadHansAnnaConversation(page);
+		const url = new URL(page.url());
+		const senderId = url.searchParams.get('senderId')!;
+		const receiverId = url.searchParams.get('receiverId')!;
+
+		const link = page.getByTestId('conv-new-doc-link');
+		await expect(link).toBeVisible();
+		const href = await link.getAttribute('href');
+		expect(href).toContain(`senderId=${senderId}`);
+		expect(href).toContain(`receiverId=${receiverId}`);
+		await page.screenshot({ path: 'test-results/e2e/conversations-new-doc-link.png' });
+	});
+
+	test('does not show swap button or new document link when only one person is selected', async ({
+		page
+	}) => {
+		await page.goto('/conversations');
+		await page.waitForURL('/conversations');
+		await expect(page.getByTestId('conv-swap-btn')).not.toBeVisible();
+		await expect(page.getByTestId('conv-new-doc-link')).not.toBeVisible();
+	});
+});