fix(staples): forward backend error status code instead of always 500

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

frontend/src/routes/household/staples/+server.ts

@@ -21,7 +21,8 @@ export const PATCH: RequestHandler = async ({ request, fetch }) => {
 	});
 
 	if (error) {
-		return json({ error: 'Failed to update ingredient' }, { status: 500 });
+		const status = (error as { status?: number }).status ?? 500;
+		return json({ error: 'Failed to update ingredient' }, { status });
 	}
 
 	return new Response(null, { status: 204 });

frontend/src/routes/household/staples/server.test.ts

@@ -46,7 +46,7 @@ describe('household staples PATCH handler', () => {
 		expect(response.status).toBe(204);
 	});
 
-	it('returns 500 when backend returns an error', async () => {
+	it('returns 500 when backend returns a 500 error', async () => {
 		mockPatch.mockResolvedValue({ data: undefined, error: { status: 500, message: 'error' } });
 
 		const response = await PATCH(createRequest({ id: 'ing-1', isStaple: false }));
@@ -54,6 +54,14 @@ describe('household staples PATCH handler', () => {
 		expect(response.status).toBe(500);
 	});
 
+	it('forwards backend 404 status when ingredient not found', async () => {
+		mockPatch.mockResolvedValue({ data: undefined, error: { status: 404 } });
+
+		const response = await PATCH(createRequest({ id: 'ing-1', isStaple: false }));
+
+		expect(response.status).toBe(404);
+	});
+
 	it('returns 400 when id is missing', async () => {
 		const response = await PATCH(createRequest({ isStaple: true }));