feat(chronik): rename route and heading to Aktivitäten

/chronik → /aktivitaeten; heading updated in all three locales.
Component folder (lib/components/chronik/) stays unchanged — internal
implementation detail, not user-facing.

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

frontend/src/routes/aktivitaeten/page.server.spec.ts

@@ -10,7 +10,7 @@ vi.mock('$lib/api.server', () => ({
 }));
 
 function buildUrl(search = ''): URL {
-	return new URL(`http://localhost/chronik${search}`);
+	return new URL(`http://localhost/aktivitaeten${search}`);
 }
 
 function mockSuccess() {
@@ -26,7 +26,7 @@ beforeEach(() => {
 	vi.clearAllMocks();
 });
 
-describe('chronik/load — core', () => {
+describe('aktivitaeten/load — core', () => {
 	it('requests only unread notifications for Für-dich', async () => {
 		mockSuccess();
 		await load({ fetch, url: buildUrl() } as never);
@@ -78,7 +78,7 @@ describe('chronik/load — core', () => {
 	});
 });
 
-describe('chronik/load — kinds param per filter', () => {
+describe('aktivitaeten/load — kinds param per filter', () => {
 	it('omits kinds for filter=alle (server defaults to ROLLUP_ELIGIBLE)', async () => {
 		mockSuccess();
 		await load({ fetch, url: buildUrl() } as never);

frontend/src/routes/profile/+page.svelte

@@ -102,7 +102,10 @@ const hasEmail = $derived(!!data.user?.email);
 		</form>
 
 		<div class="mt-4 border-t border-line pt-4">
-			<a href="/chronik" class="text-sm font-medium text-ink-2 transition-colors hover:text-ink">
+			<a
+				href="/aktivitaeten"
+				class="text-sm font-medium text-ink-2 transition-colors hover:text-ink"
+			>
 				{m.notification_history_view_link()}
 			</a>
 		</div>