houses: set cache-control once (layout already does; the page load threw header_already_set for the owner)

src/routes/trackers/houses/+page.server.ts

@@ -42,7 +42,7 @@ const int = (value: string | null) => {
 
 export const load: PageServerLoad = async (event) => {
 	requireOwner(event);
-	event.setHeaders({ 'cache-control': 'private, no-store' });
+	// cache-control is set by +layout.server.ts; setting it twice throws.
 	const params = event.url.searchParams;
 	// Defaults apply only when a filter is absent from the URL; submitting the form with a
 	// field left empty means "no limit".