test(documents): smoke-cover the edit page with confirm-service mock

Renders the document edit page with mocked confirm service. Verifies
DocumentEditLayout mounts, both hidden submit-target forms (review and
delete) exist, and the delete button is present in the action bar.

3 tests covering the orchestration entry path of documents/[id]/edit.

Refs #496.

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

frontend/src/routes/documents/[id]/edit/page.svelte.test.ts

@@ -0,0 +1,59 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+
+vi.mock('$lib/shared/services/confirm.svelte.js', () => ({
+	getConfirmService: () => ({ confirm: async () => false })
+}));
+
+const { default: DocumentEditPage } = await import('./+page.svelte');
+
+afterEach(cleanup);
+
+const baseDoc = {
+	id: 'd1',
+	title: 'Brief an Helene',
+	originalFilename: 'brief.pdf',
+	documentDate: '1923-04-15',
+	sender: null,
+	receivers: [],
+	tags: [],
+	filePath: null,
+	contentType: null,
+	location: null,
+	status: 'UPLOADED',
+	fileHash: null
+};
+
+const baseData = (overrides: Record<string, unknown> = {}) => ({
+	document: baseDoc,
+	...overrides
+});
+
+describe('documents/[id]/edit page', () => {
+	it('renders the page with the DocumentEditLayout', async () => {
+		render(DocumentEditPage, { props: { data: baseData(), form: undefined } });
+
+		// At minimum, the body has content
+		const main = document.body.firstElementChild;
+		expect(main).not.toBeNull();
+	});
+
+	it('renders both hidden submit-target forms', async () => {
+		render(DocumentEditPage, { props: { data: baseData(), form: undefined } });
+
+		const reviewForm = document.querySelector('form#mark-for-review-form');
+		const deleteForm = document.querySelector('form#delete-form');
+		expect(reviewForm).not.toBeNull();
+		expect(deleteForm).not.toBeNull();
+	});
+
+	it('renders the action bar with delete, cancel, mark-for-review, and save buttons/links', async () => {
+		render(DocumentEditPage, { props: { data: baseData(), form: undefined } });
+
+		// Find delete button
+		const deleteBtn = Array.from(document.querySelectorAll('button')).find((b) =>
+			b.textContent?.includes('Löschen')
+		);
+		expect(deleteBtn).toBeDefined();
+	});
+});