test(dashboard): exercise the EnrichmentBlock skeleton branch

Hoists the $navigating store into a shared __mocks__ module so tests can
drive it through real transitions. Adds two specs covering (a) skeleton
visible while $navigating && topDocs empty and (b) skeleton hidden when
topDocs is non-empty. Also sets aria-busy="true" on the skeleton so
screen readers announce the loading state (Leonie's a11y suggestion).

Addresses Sara's and Felix's review concern that the skeleton branch was
dead code in the test world.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/EnrichmentBlock.svelte

@@ -31,8 +31,10 @@ const showBlock = $derived(topDocs.length > 0 || bannerCount > 0 || showSkeleton
 			<DashboardNeedsMetadata topDocs={topDocs} totalCount={totalCount} />
 		{:else if showSkeleton}
 			<div
+				data-testid="enrichment-block-skeleton"
 				class="h-[360px] animate-pulse rounded-sm border border-line bg-surface/50 motion-reduce:animate-none"
-				aria-hidden="true"
+				aria-busy="true"
+				aria-label="Lade aktualisierte Liste"
 			></div>
 		{/if}
 	</div>

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

@@ -2,14 +2,20 @@ import { describe, it, expect, afterEach, vi } from 'vitest';
 import { cleanup, render } from 'vitest-browser-svelte';
 import { page } from 'vitest/browser';
 
+// The store must live in a separate module because vi.mock factories are
+// hoisted and cannot reference top-level variables defined in this file.
+import { navigatingStore } from './__mocks__/navigatingStore';
 import EnrichmentBlock from './EnrichmentBlock.svelte';
 
 vi.mock('$app/stores', async () => {
-	const { writable } = await import('svelte/store');
+	const mod = await import('./__mocks__/navigatingStore');
-	return { navigating: writable(null) };
+	return { navigating: mod.navigatingStore };
 });
 
-afterEach(cleanup);
+afterEach(() => {
+	cleanup();
+	navigatingStore.set(null);
+});
 
 type Doc = { id: string; title: string; uploadedAt: string };
 
@@ -58,4 +64,26 @@ describe('EnrichmentBlock', () => {
 		await expect.element(page.getByRole('status')).toBeInTheDocument();
 		await expect.element(page.getByTestId('dashboard-needs-metadata')).toBeInTheDocument();
 	});
+
+	it('renders the skeleton when $navigating is active and topDocs is empty', async () => {
+		navigatingStore.set({ type: 'link' });
+		render(EnrichmentBlock, {
+			topDocs: [],
+			totalCount: 0,
+			bannerCount: 0,
+			onBannerClose: vi.fn()
+		});
+		await expect.element(page.getByTestId('enrichment-block-skeleton')).toBeInTheDocument();
+	});
+
+	it('does not render the skeleton when topDocs is non-empty even during $navigating', async () => {
+		navigatingStore.set({ type: 'link' });
+		render(EnrichmentBlock, {
+			topDocs: [doc('d1')],
+			totalCount: 1,
+			bannerCount: 0,
+			onBannerClose: vi.fn()
+		});
+		await expect.element(page.getByTestId('enrichment-block-skeleton')).not.toBeInTheDocument();
+	});
 });

frontend/src/lib/components/__mocks__/navigatingStore.ts

@@ -0,0 +1,3 @@
+import { writable } from 'svelte/store';
+
+export const navigatingStore = writable<unknown | null>(null);