Reduce terminal detail refresh traffic

frontend/components/dashboard/scan-terminal/__tests__/proxyCachePolicy.test.ts

@@ -20,6 +20,7 @@ export function runTests() {
   const cached = buildCityDetailProxyCachePolicy("false", 15);
   assert.equal(cached.fetchMode, "revalidate");
   assert.equal(cached.revalidateSeconds, 15);
+  assert.match(cached.responseCacheControl, /max-age=15/);
   assert.match(cached.responseCacheControl, /s-maxage=15/);
 
   const scanForced = buildForceRefreshProxyCachePolicy("true", 10);

frontend/components/dashboard/scan-terminal/__tests__/refreshCadencePolicy.test.ts

@@ -76,6 +76,12 @@ export async function runTests() {
       chartSource.includes("setHourly(data)"),
     "visible chart fallback must refresh the full city detail payload at the current chart resolution when SSE patches stop",
   );
+  assert(
+    chartLogicSource.includes("HOURLY_FORCE_REFRESH_DEDUP_MS") &&
+      chartLogicSource.includes("maxAgeMs: HOURLY_FORCE_REFRESH_DEDUP_MS") &&
+      chartLogicSource.includes("recentlyRefreshed.data"),
+    "forced chart detail refreshes should reuse a very recent full-detail payload instead of refetching repeatedly",
+  );
   assert(
     __shouldPollLiveChartForTest({ city: "shanghai", compact: true, isActive: false, isMaximized: false }) === true,
     "compact grid slots are visible charts and should run the no-patch fallback guard",