test(TranscriptionReadView): cover hover card timer and keyboard focus behavior

Five new tests verify:
- Card stays open when mouse moves mention → card (cancels 150ms timer)
- Card closes immediately on card mouseleave (no timer)
- Re-entering a mention cancels a pending close
- Card stays open when keyboard focus moves mention → card (WCAG 2.1.1)
- Card closes when keyboard focus leaves the card entirely

The keyboard tests drove adding onfocusin/onfocusout to PersonHoverCard's
root div, reusing the existing onmouseenter/onmouseleave callbacks so that
screen-reader and keyboard users get the same stay-open affordance as
mouse users. relatedTarget check prevents spurious closes on intra-card
focus movement.

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

frontend/src/lib/components/PersonHoverCard.svelte

@@ -94,6 +94,12 @@ const showMaidenName = $derived(
 	style:left={`${position.left}px`}
 	onmouseenter={onmouseenter}
 	onmouseleave={onmouseleave}
+	onfocusin={onmouseenter}
+	onfocusout={(e) => {
+		if (!(e.currentTarget as HTMLElement).contains(e.relatedTarget as Node | null)) {
+			onmouseleave?.();
+		}
+	}}
 >
 	{#if state.status === 'loading'}
 		<div

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

@@ -0,0 +1,170 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import TranscriptionReadView from './TranscriptionReadView.svelte';
+import type { TranscriptionBlockData } from '$lib/types';
+
+const PERSON_ID = '11111111-0000-0000-0000-000000000001';
+
+const block: TranscriptionBlockData = {
+	id: 'b1',
+	annotationId: 'a1',
+	documentId: 'd1',
+	text: '@Auguste',
+	label: null,
+	sortOrder: 0,
+	version: 1,
+	source: 'MANUAL',
+	reviewed: false,
+	mentionedPersons: [{ personId: PERSON_ID, displayName: 'Auguste' }]
+};
+
+function mockPersonFetch() {
+	vi.stubGlobal(
+		'fetch',
+		vi.fn().mockImplementation((url: string) => {
+			if (url.includes('/relationships')) {
+				return Promise.resolve({ ok: true, json: () => Promise.resolve([]) });
+			}
+			return Promise.resolve({
+				ok: true,
+				status: 200,
+				json: () =>
+					Promise.resolve({
+						id: PERSON_ID,
+						firstName: 'Auguste',
+						lastName: 'Raddatz',
+						displayName: 'Auguste Raddatz'
+					})
+			});
+		})
+	);
+}
+
+function getMentionLink(): HTMLAnchorElement {
+	return document.querySelector(
+		`a.person-mention[data-person-id="${PERSON_ID}"]`
+	) as HTMLAnchorElement;
+}
+
+function getHoverCard(): HTMLElement | null {
+	return document.querySelector('[data-testid="person-hover-card"]');
+}
+
+/** Hover a mention and wait until the loaded card content is in the DOM. */
+async function showCard(): Promise<void> {
+	getMentionLink().dispatchEvent(new MouseEvent('mouseenter', { bubbles: false }));
+	await vi.waitFor(() => {
+		expect(document.querySelector('[data-testid="person-hover-card-content"]')).not.toBeNull();
+	});
+}
+
+afterEach(() => {
+	cleanup();
+	vi.unstubAllGlobals();
+});
+
+// ─── Mouse timer behavior ──────────────────────────────────────────────────────
+
+describe('TranscriptionReadView — hover card mouse timer', () => {
+	it('keeps the card open when mouse moves from mention to card within 150ms', async () => {
+		mockPersonFetch();
+		render(TranscriptionReadView, { blocks: [block], onParagraphClick: () => {} });
+
+		await showCard();
+
+		// Leave mention — starts 150ms close timer
+		getMentionLink().dispatchEvent(new MouseEvent('mouseleave', { bubbles: false }));
+
+		// Enter card before 150ms — cancels timer
+		getHoverCard()!.dispatchEvent(new MouseEvent('mouseenter'));
+
+		// Wait past the original 150ms window
+		await new Promise((r) => setTimeout(r, 200));
+
+		expect(getHoverCard()).not.toBeNull();
+	});
+
+	it('closes the card immediately when mouse leaves the card (no timer)', async () => {
+		mockPersonFetch();
+		render(TranscriptionReadView, { blocks: [block], onParagraphClick: () => {} });
+
+		await showCard();
+
+		// Leave card — activeCard = null immediately, no timer
+		getHoverCard()!.dispatchEvent(new MouseEvent('mouseleave'));
+
+		await vi.waitFor(() => {
+			expect(getHoverCard()).toBeNull();
+		});
+	});
+
+	it('cancels a pending close when mouse re-enters a mention', async () => {
+		mockPersonFetch();
+		render(TranscriptionReadView, { blocks: [block], onParagraphClick: () => {} });
+
+		await showCard();
+
+		// Leave mention — starts 150ms close timer
+		getMentionLink().dispatchEvent(new MouseEvent('mouseleave', { bubbles: false }));
+
+		// Re-enter same mention before 150ms — cancels timer
+		getMentionLink().dispatchEvent(new MouseEvent('mouseenter', { bubbles: false }));
+
+		// Wait past the original 150ms window
+		await new Promise((r) => setTimeout(r, 200));
+
+		expect(getHoverCard()).not.toBeNull();
+	});
+});
+
+// ─── Keyboard focus behavior ───────────────────────────────────────────────────
+
+describe('TranscriptionReadView — hover card keyboard focus', () => {
+	it('keeps the card open when keyboard focus moves from mention into card', async () => {
+		mockPersonFetch();
+		render(TranscriptionReadView, { blocks: [block], onParagraphClick: () => {} });
+
+		// Show card via keyboard focusin on mention
+		getMentionLink().dispatchEvent(new FocusEvent('focusin', { bubbles: true }));
+		await vi.waitFor(() => {
+			expect(document.querySelector('[data-testid="person-hover-card-content"]')).not.toBeNull();
+		});
+
+		// Focus leaves mention — starts 150ms close timer
+		getMentionLink().dispatchEvent(new FocusEvent('focusout', { bubbles: true }));
+
+		// Focus enters card — should cancel the close timer
+		getHoverCard()!.dispatchEvent(new FocusEvent('focusin', { bubbles: true }));
+
+		// Wait past the 150ms window
+		await new Promise((r) => setTimeout(r, 200));
+
+		expect(getHoverCard()).not.toBeNull();
+	});
+
+	it('closes the card when keyboard focus leaves the card entirely', async () => {
+		mockPersonFetch();
+		render(TranscriptionReadView, { blocks: [block], onParagraphClick: () => {} });
+
+		// Show card via keyboard focusin
+		getMentionLink().dispatchEvent(new FocusEvent('focusin', { bubbles: true }));
+		await vi.waitFor(() => {
+			expect(document.querySelector('[data-testid="person-hover-card-content"]')).not.toBeNull();
+		});
+
+		// Focus leaves mention — 150ms timer starts
+		getMentionLink().dispatchEvent(new FocusEvent('focusout', { bubbles: true }));
+
+		// Focus enters card — cancels timer
+		getHoverCard()!.dispatchEvent(new FocusEvent('focusin', { bubbles: true }));
+
+		// Focus leaves card entirely (relatedTarget = null means focus left the page)
+		getHoverCard()!.dispatchEvent(
+			new FocusEvent('focusout', { bubbles: true, relatedTarget: null })
+		);
+
+		await vi.waitFor(() => {
+			expect(getHoverCard()).toBeNull();
+		});
+	});
+});