test(routes): expand AppNav coverage for active links and mobile overlay

Active-link styling per pathname (documents, persons, stammbaum,
geschichten, admin), mobile backdrop click closes nav, Escape
keypress on overlay closes nav.

7 new tests targeting ~14 branches.

Refs #496.

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

frontend/src/routes/AppNav.svelte.test.ts

@@ -75,4 +75,83 @@ describe('AppNav', () => {
 			.element(browserPage.getByRole('button', { name: /menü schließen/i }))
 			.toHaveAttribute('aria-expanded', 'true');
 	});
+
+	it('marks the documents link as active when pathname starts with /documents', async () => {
+		mockPage.url = new URL('http://localhost/documents/abc');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		const link = Array.from(document.querySelectorAll('nav a[href="/documents"]'))[0];
+		expect(link?.className).toContain('border-accent');
+	});
+
+	it('marks the persons link as active when pathname starts with /persons', async () => {
+		mockPage.url = new URL('http://localhost/persons/123');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		const link = Array.from(document.querySelectorAll('nav a[href="/persons"]'))[0];
+		expect(link?.className).toContain('border-accent');
+	});
+
+	it('marks the stammbaum link as active when pathname starts with /stammbaum', async () => {
+		mockPage.url = new URL('http://localhost/stammbaum');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		const link = Array.from(document.querySelectorAll('nav a[href="/stammbaum"]'))[0];
+		expect(link?.className).toContain('border-accent');
+	});
+
+	it('marks the geschichten link as active when pathname starts with /geschichten', async () => {
+		mockPage.url = new URL('http://localhost/geschichten/x');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		const link = Array.from(document.querySelectorAll('nav a[href="/geschichten"]'))[0];
+		expect(link?.className).toContain('border-accent');
+	});
+
+	it('marks the admin link as active when pathname starts with /admin and isAdmin is true', async () => {
+		mockPage.url = new URL('http://localhost/admin/users');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: true } });
+
+		const link = Array.from(document.querySelectorAll('nav a[href="/admin"]'))[0];
+		expect(link?.className).toContain('border-accent');
+	});
+
+	it('closes the mobile nav when the backdrop is clicked', async () => {
+		mockPage.url = new URL('http://localhost/');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		await browserPage.getByRole('button', { name: /menü öffnen/i }).click();
+
+		// Mobile nav is now open
+		const backdrop = document.querySelector('.bg-black\\/20') as HTMLElement;
+		expect(backdrop).not.toBeNull();
+		backdrop.click();
+
+		await new Promise((r) => setTimeout(r, 30));
+		await expect
+			.element(browserPage.getByRole('button', { name: /menü öffnen/i }))
+			.toHaveAttribute('aria-expanded', 'false');
+	});
+
+	it('closes the mobile nav when Escape is pressed on the overlay', async () => {
+		mockPage.url = new URL('http://localhost/');
+		const AppNav = await loadComponent();
+		render(AppNav, { props: { isAdmin: false } });
+
+		await browserPage.getByRole('button', { name: /menü öffnen/i }).click();
+
+		const overlay = document.querySelector('.fixed.inset-0') as HTMLElement;
+		overlay.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true }));
+
+		await new Promise((r) => setTimeout(r, 30));
+		await expect
+			.element(browserPage.getByRole('button', { name: /menü öffnen/i }))
+			.toHaveAttribute('aria-expanded', 'false');
+	});
 });