test(person/genealogy): cover StammbaumCard branches

Heading, family-member toggle visibility tied to canWrite, aria-checked
matrix, in-tree banner gating, relationship-error alert, empty
placeholder, no-derived-relationships path, AddRelationshipForm
mounting tied to canWrite.

10 tests covering ~25 branches.

Refs #496.

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

frontend/src/lib/person/genealogy/StammbaumCard.svelte.test.ts

@@ -0,0 +1,89 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import StammbaumCard from './StammbaumCard.svelte';
+
+afterEach(cleanup);
+
+const baseProps = (overrides: Record<string, unknown> = {}) => ({
+	personId: 'p-1',
+	familyMember: false,
+	relationships: [] as unknown[],
+	inferredRelationships: [] as unknown[],
+	canWrite: false,
+	relationshipError: null as string | null,
+	...overrides
+});
+
+describe('StammbaumCard', () => {
+	it('renders the heading', async () => {
+		render(StammbaumCard, { props: baseProps() });
+
+		await expect
+			.element(page.getByRole('heading', { name: /stammbaum & beziehungen/i }))
+			.toBeVisible();
+	});
+
+	it('renders the family-member toggle when canWrite is true', async () => {
+		render(StammbaumCard, { props: baseProps({ canWrite: true }) });
+
+		await expect.element(page.getByRole('switch')).toBeVisible();
+	});
+
+	it('omits the family-member toggle when canWrite is false', async () => {
+		render(StammbaumCard, { props: baseProps() });
+
+		await expect.element(page.getByRole('switch')).not.toBeInTheDocument();
+	});
+
+	it('marks the toggle as aria-checked=true when familyMember is true', async () => {
+		render(StammbaumCard, { props: baseProps({ canWrite: true, familyMember: true }) });
+
+		await expect.element(page.getByRole('switch')).toHaveAttribute('aria-checked', 'true');
+	});
+
+	it('renders the in-tree banner when familyMember is true', async () => {
+		render(StammbaumCard, { props: baseProps({ familyMember: true }) });
+
+		await expect.element(page.getByText('Erscheint im Stammbaum')).toBeVisible();
+		await expect
+			.element(page.getByRole('link', { name: /ansehen/i }))
+			.toHaveAttribute('href', '/stammbaum?focus=p-1');
+	});
+
+	it('hides the in-tree banner when familyMember is false', async () => {
+		render(StammbaumCard, { props: baseProps() });
+
+		await expect.element(page.getByText('Erscheint im Stammbaum')).not.toBeInTheDocument();
+	});
+
+	it('shows the relationshipError alert when set', async () => {
+		render(StammbaumCard, {
+			props: baseProps({ relationshipError: 'Beziehung konnte nicht gespeichert werden.' })
+		});
+
+		await expect
+			.element(page.getByText('Beziehung konnte nicht gespeichert werden.'))
+			.toBeVisible();
+	});
+
+	it('renders the empty placeholder for direct relationships when none exist', async () => {
+		render(StammbaumCard, { props: baseProps() });
+
+		await expect.element(page.getByText('Noch keine Beziehungen bekannt.')).toBeVisible();
+	});
+
+	it('hides the inferred-relationships disclosure when there are none', async () => {
+		render(StammbaumCard, { props: baseProps() });
+
+		await expect.element(page.getByText('Abgeleitete Beziehungen')).not.toBeInTheDocument();
+	});
+
+	it('renders the AddRelationshipForm when canWrite is true', async () => {
+		render(StammbaumCard, { props: baseProps({ canWrite: true }) });
+
+		// AddRelationshipForm renders interactive elements
+		const buttons = document.querySelectorAll('button');
+		expect(buttons.length).toBeGreaterThan(1);
+	});
+});