test(e2e): add coverage for all 12 critical journeys (TEST-3 #405)

Adds docs/audits/e2e-coverage-report.md mapping all 12 critical journeys
to their test files. Fills the 6 coverage gaps with new e2e tests:

- J1: Register via invite code (auth.spec.ts)
- J3: Edit document tags via TagInput (documents.spec.ts)
- J4: Create brand-new tag via TagInput (documents.spec.ts)
- J5: Add SPOUSE_OF relationship on person edit page (persons.spec.ts)
- J6: Multi-filter search (text + date, text + tagId) (documents.spec.ts)
- J10: Notification bell opens dropdown (notification-deep-link.spec.ts)
- J11: Non-admin blocked from /admin/* (permissions.spec.ts)
- J12: Mass import trigger shows status (admin.spec.ts)

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

frontend/e2e/persons.spec.ts

@@ -181,3 +181,61 @@ test.describe('Person detail — sent and received documents', () => {
 		// If no person has dated documents, the test is a no-op (year range is optional)
 	});
 });
+
+// ── J5: Add a relationship on the person edit page ────────────────────────
+//
+// Creates two persons via API, then opens the first person's edit page and
+// uses the AddRelationshipForm to link them. Asserts the chip appears.
+
+test.describe('Person relationship — add via edit page (J5)', () => {
+	const baseURL = process.env.E2E_BASE_URL ?? 'http://localhost:3000';
+	let personAHref: string;
+	let personBName: string;
+
+	test.beforeAll(async ({ request }) => {
+		const stamp = Date.now().toString(36);
+
+		const aRes = await request.post('/api/persons', {
+			data: { firstName: 'E2E-Rel-A', lastName: stamp }
+		});
+		if (!aRes.ok()) throw new Error(`Create person A failed: ${aRes.status()}`);
+		const a = await aRes.json();
+		personAHref = `${baseURL}/persons/${a.id}`;
+
+		const bRes = await request.post('/api/persons', {
+			data: { firstName: 'E2E-Rel-B', lastName: stamp }
+		});
+		if (!bRes.ok()) throw new Error(`Create person B failed: ${bRes.status()}`);
+		const b = await bRes.json();
+		personBName = b.displayName ?? `E2E-Rel-B ${stamp}`;
+	});
+
+	test('user adds a SPOUSE_OF relationship and sees the chip on the edit page', async ({
+		page
+	}) => {
+		await page.goto(`${personAHref}/edit`);
+		await page.waitForSelector('[data-hydrated]');
+
+		// Open the AddRelationshipForm by clicking the "+ Beziehung hinzufügen" button.
+		await page.getByRole('button', { name: '+ Beziehung hinzufügen' }).click();
+
+		// Select SPOUSE_OF from the type dropdown.
+		await page.selectOption('select[name="relationType"]', 'SPOUSE_OF');
+
+		// Type person B's name in the PersonTypeahead.
+		const personInput = page.getByRole('combobox', { name: /Person/i });
+		await expect(personInput).toBeVisible({ timeout: 5_000 });
+		await personInput.fill('E2E-Rel-B');
+
+		const suggestion = page.getByRole('option').first();
+		await expect(suggestion).toBeVisible({ timeout: 5_000 });
+		await suggestion.click();
+
+		// Submit the relationship form.
+		await page.getByRole('button', { name: 'Hinzufügen' }).click();
+
+		// The relationship chip should appear in the Stammbaum section.
+		await expect(page.getByText(personBName)).toBeVisible({ timeout: 8_000 });
+		await page.screenshot({ path: 'test-results/e2e/person-relationship-added.png' });
+	});
+});