test(journey-editor): add red test — PATCH body must send {"note":null} not {}

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

frontend/src/lib/geschichte/JourneyEditor.svelte.spec.ts

@@ -310,6 +310,38 @@ describe('JourneyEditor — live announce region', () => {
 	});
 });
 
+describe('JourneyEditor — note patch body', () => {
+	it('sends {"note":null} when note textarea is cleared and blurred', async () => {
+		const items = [
+			{ id: 'i1', position: 0, document: docSummary('d1', 'Brief A'), note: 'old note' }
+		];
+		vi.stubGlobal(
+			'fetch',
+			vi.fn().mockResolvedValue({
+				ok: true,
+				json: vi
+					.fn()
+					.mockResolvedValue({ id: 'i1', position: 0, document: docSummary('d1', 'Brief A') })
+			})
+		);
+
+		render(JourneyEditor, defaultProps({ geschichte: makeGeschichte({ items }) }));
+
+		const textarea = page.getByRole('textbox', { name: /Kuratoren-Notiz/ });
+		await userEvent.clear(textarea);
+		await textarea.element().dispatchEvent(new FocusEvent('blur'));
+		await new Promise((r) => setTimeout(r, 50));
+
+		expect(globalThis.fetch).toHaveBeenCalledWith(
+			expect.stringContaining('/items/i1'),
+			expect.objectContaining({
+				method: 'PATCH',
+				body: JSON.stringify({ note: null })
+			})
+		);
+	});
+});
+
 describe('JourneyEditor — duplicate document aria-disabled', () => {
 	it('already-added document appears as aria-disabled in picker', async () => {
 		const items = [{ id: 'i1', position: 0, document: docSummary('d1', 'Brief von Karl') }];