test(person-mention): replace setTimeout waits with vi.waitFor

Sara #1 + Felix #4: setTimeout(r, 50) and setTimeout(r, 5) were racing the
microtask queue — passes on a fast laptop, will fail on a loaded CI runner.
Replace all six occurrences with vi.waitFor(() => expect(...)) which polls
until the assertion passes (default 1s timeout, 10ms interval).

Tests are now deterministic — they pass the moment the condition is true,
fail the moment the timeout elapses, and never spuriously time out on slow
CI hardware.

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

frontend/src/lib/components/TranscriptionReadView.svelte.test.ts

@@ -280,13 +280,14 @@ describe('TranscriptionReadView — person-mention rendering', () => {
 
 		const link = document.querySelector('a.person-mention')!;
 		link.dispatchEvent(new MouseEvent('mouseenter', { bubbles: true }));
-		await new Promise((r) => setTimeout(r, 10));
 
+		await vi.waitFor(() => {
 			const personFetches = fetchMock.mock.calls.filter((c) =>
 				String(c[0]).includes(`/api/persons/${PERSON_ID}`)
 			);
 			expect(personFetches.length).toBeGreaterThanOrEqual(1);
 		});
+	});
 
 	it('deduplicates fetches for the same personId across multiple mouseenter events (B15.5)', async () => {
 		const fetchMock = vi.fn().mockResolvedValue({
@@ -308,13 +309,13 @@ describe('TranscriptionReadView — person-mention rendering', () => {
 		// Plus a re-hover on the first
 		links[0].dispatchEvent(new MouseEvent('mouseenter', { bubbles: true }));
 
-		await new Promise((r) => setTimeout(r, 10));
+		await vi.waitFor(() => {
-
 			const personFetches = fetchMock.mock.calls.filter(
 				(c) => String(c[0]) === `/api/persons/${PERSON_ID}`
 			);
 			expect(personFetches.length).toBe(1);
 		});
+	});
 
 	it('mounts the hover card on mouseenter when the fetch loads', async () => {
 		vi.stubGlobal(
@@ -349,10 +350,11 @@ describe('TranscriptionReadView — person-mention rendering', () => {
 		const link = document.querySelector('a.person-mention')!;
 		link.dispatchEvent(new MouseEvent('mouseenter', { bubbles: true }));
 
-		await new Promise((r) => setTimeout(r, 50));
+		await vi.waitFor(() => {
 			const card = document.querySelector('[data-testid="person-hover-card"]');
 			expect(card).not.toBeNull();
 		});
+	});
 
 	it('unmounts the hover card on mouseleave', async () => {
 		render(TranscriptionReadView, {
@@ -362,13 +364,13 @@ describe('TranscriptionReadView — person-mention rendering', () => {
 
 		const link = document.querySelector('a.person-mention')!;
 		link.dispatchEvent(new MouseEvent('mouseenter', { bubbles: true }));
-		await new Promise((r) => setTimeout(r, 5));
 		link.dispatchEvent(new MouseEvent('mouseleave', { bubbles: true }));
-		await new Promise((r) => setTimeout(r, 5));
 
+		await vi.waitFor(() => {
 			const card = document.querySelector('[data-testid="person-hover-card"]');
 			expect(card).toBeNull();
 		});
+	});
 
 	it('mounts the hover card on focusin so keyboard users see the preview (WCAG 2.1.1)', async () => {
 		vi.stubGlobal(
@@ -468,13 +470,15 @@ describe('TranscriptionReadView — person-mention rendering', () => {
 
 		const link = document.querySelector('a.person-mention')!;
 		link.dispatchEvent(new MouseEvent('mouseenter', { bubbles: true }));
-		await new Promise((r) => setTimeout(r, 50));
 
-		// 404 → no card mounted
+		await vi.waitFor(() => {
-		const card = document.querySelector('[data-testid="person-hover-card"]');
-		expect(card).toBeNull();
 			// Anchor is marked as deleted so subsequent hovers/clicks treat it as plain text
 			const stillLink = document.querySelector('a.person-mention')!;
 			expect(stillLink.getAttribute('data-person-deleted')).toBe('true');
 		});
+
+		// 404 → no card mounted
+		const card = document.querySelector('[data-testid="person-hover-card"]');
+		expect(card).toBeNull();
+	});
 });