perf: reduce worker overview refetches

apps/frontend/src/pages/worker/WorkerHallPage.tsx

@@ -111,6 +111,8 @@ export default function WorkerHallPage() {
         problemCount: Number(summaryByStatus.get('problem') || 0),
       } satisfies HallSummary
     },
+    staleTime: 5_000,
+    refetchOnWindowFocus: false,
     retry: false,
   })
 

apps/frontend/src/pages/worker/WorkerOrdersPage.tsx

@@ -197,6 +197,8 @@ export default function WorkerOrdersPage() {
   const overviewQuery = useQuery({
     queryKey: ['worker-my-orders-overview'],
     queryFn: fetchWorkerMyOrderOverview,
+    staleTime: 5_000,
+    refetchOnWindowFocus: false,
     retry: false,
   })
   const cancelRequestsQuery = useQuery({