test(routes): expand aktivitaeten page coverage

loadError branches (FuerDichBox skipped vs shown), first-run vs
filter-empty empty-state variants, timeline rendering when feed
has items, FilterPills + FuerDichBox conditional render.

7 tests covering ~12 branches in the page file.

Refs #496.

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

frontend/src/routes/aktivitaeten/page.svelte.test.ts

@@ -63,17 +63,87 @@ describe('aktivitaeten page', () => {
 		// ChronikErrorCard renders some retry mechanism
 		const main = document.querySelector('main');
 		expect(main).not.toBeNull();
+		// FuerDichBox should NOT render when loadError is set
+		const fuerDich = document.querySelector('[data-testid="chronik-inbox-zero"]');
+		expect(fuerDich).toBeNull();
 	});
 
-	it('renders the empty state when activityFeed is empty', async () => {
+	it('renders the FuerDichBox and FilterPills when loadError is null', async () => {
 		render(AktivitaetenPage, { props: { data: baseData() } });
 
-		const main = document.querySelector('main');
-		expect(main).not.toBeNull();
+		// FuerDichBox shows the inbox-zero state when no unread
+		const fuerDich = document.querySelector('[data-testid="chronik-inbox-zero"]');
+		expect(fuerDich).not.toBeNull();
+
+		// FilterPills present
+		const radiogroup = document.querySelector('[role="radiogroup"]');
+		expect(radiogroup).not.toBeNull();
 	});
 
-	it('renders without crashing when filter is set to non-default value', async () => {
-		render(AktivitaetenPage, { props: { data: baseData({ filter: 'mentions' as const }) } });
+	it('renders the first-run empty state when activityFeed is empty', async () => {
+		render(AktivitaetenPage, { props: { data: baseData() } });
+
+		const empty = document.querySelector('[data-testid="chronik-empty-state"]');
+		expect(empty?.getAttribute('data-variant')).toBe('first-run');
+	});
+
+	it('renders the filter-empty empty state when feed has items but filter rules out all', async () => {
+		render(AktivitaetenPage, {
+			props: {
+				data: baseData({
+					filter: 'fuer-dich' as const,
+					activityFeed: [
+						{
+							kind: 'TEXT_SAVED',
+							documentId: 'doc-1',
+							documentTitle: 'Brief',
+							actor: { id: 'u1', name: 'Anna', initials: 'AS', color: '#000' },
+							count: 1,
+							happenedAt: '2026-01-01T00:00:00Z',
+							happenedAtUntil: null,
+							youMentioned: false
+						}
+					]
+				})
+			}
+		});
+
+		const empty = document.querySelector('[data-testid="chronik-empty-state"]');
+		expect(empty?.getAttribute('data-variant')).toBe('filter-empty');
+	});
+
+	it('renders the timeline when displayFeed is non-empty', async () => {
+		render(AktivitaetenPage, {
+			props: {
+				data: baseData({
+					filter: 'alle' as const,
+					activityFeed: [
+						{
+							kind: 'TEXT_SAVED',
+							documentId: 'doc-1',
+							documentTitle: 'Brief 1899',
+							actor: { id: 'u1', name: 'Anna', initials: 'AS', color: '#000' },
+							count: 1,
+							happenedAt: '2026-01-01T00:00:00Z',
+							happenedAtUntil: null,
+							youMentioned: false
+						}
+					]
+				})
+			}
+		});
+
+		// Timeline renders the document title from the feed item
+		expect(document.body.textContent).toContain('Brief 1899');
+		// No empty-state in this case
+		const empty = document.querySelector('[data-testid="chronik-empty-state"]');
+		expect(empty).toBeNull();
+	});
+
+	it('renders without crashing when filter is set to a non-default value', async () => {
+		render(AktivitaetenPage, {
+			props: { data: baseData({ filter: 'transkription' as const }) }
+		});
 
 		const main = document.querySelector('main');
 		expect(main).not.toBeNull();