feat(bulk-edit): add canWrite-gated row checkboxes on /documents and /enrich

Each row in the document search list and the enrichment queue gets a
WCAG-compliant (44px touch target) checkbox bound to bulkSelectionStore.
Checkbox click does not trigger the row's stretched-link navigation —
it sits inside the z-10 content sibling, the link is in the z-0 sibling,
so click events do not bubble between them.

Refs #225

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

frontend/src/lib/components/DocumentRow.svelte

@@ -4,13 +4,14 @@ import type { components } from '$lib/generated/api';
 import { applyOffsets } from '$lib/search';
 import { formatDate } from '$lib/utils/date';
 import * as m from '$lib/paraglide/messages.js';
+import { bulkSelectionStore } from '$lib/stores/bulkSelection.svelte';
 import ProgressRing from './ProgressRing.svelte';
 import ContributorStack from './ContributorStack.svelte';
 import DocumentThumbnail from './DocumentThumbnail.svelte';
 
 type DocumentSearchItem = components['schemas']['DocumentSearchItem'];
 
-let { item }: { item: DocumentSearchItem } = $props();
+let { item, canWrite = false }: { item: DocumentSearchItem; canWrite?: boolean } = $props();
 
 const doc = $derived(item.document);
 const titleText = $derived(doc.title || doc.originalFilename);
@@ -55,6 +56,21 @@ function safeTagColor(color: string | null | undefined): string {
 	<a href="/documents/{doc.id}" aria-label={titleText} class="absolute inset-0 z-0 block"></a>
 	<div class="pointer-events-none relative z-10 px-4 py-4 sm:py-5">
 		<div class="flex gap-3 sm:gap-5">
+			<!-- Bulk-selection checkbox -->
+			{#if canWrite}
+				<label
+					class="pointer-events-auto flex min-h-[44px] min-w-[44px] flex-shrink-0 cursor-pointer items-start pt-1"
+					data-testid="bulk-select-checkbox"
+				>
+					<input
+						type="checkbox"
+						class="h-5 w-5 cursor-pointer accent-brand-navy"
+						checked={bulkSelectionStore.has(doc.id)}
+						onchange={() => bulkSelectionStore.toggle(doc.id)}
+						aria-label={m.bulk_edit_select_document({ title: titleText })}
+					/>
+				</label>
+			{/if}
 			<!-- Thumbnail tile -->
 			<DocumentThumbnail doc={doc} size="lg" />
 

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

@@ -3,6 +3,7 @@ import { cleanup, render } from 'vitest-browser-svelte';
 import { page } from 'vitest/browser';
 import { goto } from '$app/navigation';
 import DocumentRow from './DocumentRow.svelte';
+import { bulkSelectionStore } from '$lib/stores/bulkSelection.svelte';
 import type { components } from '$lib/generated/api';
 
 vi.mock('$app/navigation', () => ({ goto: vi.fn() }));
@@ -10,6 +11,7 @@ vi.mock('$app/navigation', () => ({ goto: vi.fn() }));
 afterEach(() => {
 	cleanup();
 	vi.mocked(goto).mockClear();
+	bulkSelectionStore.clear();
 });
 
 type DocumentSearchItem = components['schemas']['DocumentSearchItem'];
@@ -265,6 +267,45 @@ describe('DocumentRow – tags', () => {
 	});
 });
 
+// ─── Bulk-selection checkbox ─────────────────────────────────────────────────
+
+describe('DocumentRow – bulk selection checkbox', () => {
+	it('does not render the checkbox when canWrite is false', async () => {
+		render(DocumentRow, { item: makeItem(), canWrite: false });
+		await expect.element(page.getByTestId('bulk-select-checkbox')).not.toBeInTheDocument();
+	});
+
+	it('renders the checkbox when canWrite is true', async () => {
+		render(DocumentRow, { item: makeItem(), canWrite: true });
+		await expect.element(page.getByTestId('bulk-select-checkbox')).toBeInTheDocument();
+	});
+
+	it('checkbox aria-label includes the document title', async () => {
+		const item = makeItem({ document: { ...makeItem().document, title: 'Brief an Anna' } });
+		render(DocumentRow, { item, canWrite: true });
+		await expect
+			.element(page.getByRole('checkbox', { name: /Brief an Anna/i }))
+			.toBeInTheDocument();
+	});
+
+	it('toggling the checkbox calls bulkSelectionStore.toggle', async () => {
+		const item = makeItem({ document: { ...makeItem().document, id: 'doc-42' } });
+		render(DocumentRow, { item, canWrite: true });
+		expect(bulkSelectionStore.has('doc-42')).toBe(false);
+
+		document.querySelector<HTMLInputElement>('input[type="checkbox"]')?.click();
+
+		await expect.poll(() => bulkSelectionStore.has('doc-42')).toBe(true);
+	});
+
+	it('checked state mirrors the store', async () => {
+		bulkSelectionStore.add('doc-99');
+		const item = makeItem({ document: { ...makeItem().document, id: 'doc-99' } });
+		render(DocumentRow, { item, canWrite: true });
+		await expect.element(page.getByRole('checkbox')).toBeChecked();
+	});
+});
+
 // ─── ProgressRing & ContributorStack ─────────────────────────────────────────
 
 describe('DocumentRow – progress ring and contributors', () => {