feat: implement scan terminal service with AI-powered city analysis and caching support

frontend/components/dashboard/scan-terminal/AiPinnedForecastView.tsx

@@ -155,7 +155,7 @@ function AiPinnedCityCard({
   const { aiForecast, refreshAiForecast } = useAiCityForecast({
     detail,
     detailCityName,
-    enabled: Boolean(detail && !collapsed),
+    enabled: Boolean(detail),
     isEn,
     locale,
     report,
@@ -163,7 +163,7 @@ function AiPinnedCityCard({
   const { marketScan, marketStatus } = useCityMarketScan({
     detail,
     detailCityName,
-    enabled: Boolean(detail && !collapsed),
+    enabled: Boolean(detail),
   });
 
   const aiCityForecast = aiForecast.payload?.city_forecast || null;
@@ -572,7 +572,6 @@ export function AiPinnedForecastView({
       items.forEach((item) => {
         const stableKey = normalizeCityKey(item.cityName) || item.cityName;
         if (!knownCityKeysRef.current.has(stableKey)) {
-          next.add(stableKey);
           changed = true;
         }
       });

frontend/components/dashboard/scan-terminal/use-ai-city-card-data.ts

@@ -82,6 +82,16 @@ function writeCachedPayload<T>(key: string, payload: T) {
   }
 }
 
+function removeCachedPayload(key: string) {
+  const storage = getStorage();
+  if (!storage) return;
+  try {
+    storage.removeItem(key);
+  } catch {
+    // Ignore privacy-mode failures; the next network request can still proceed.
+  }
+}
+
 function parseAiCityStreamBlock(block: string): AiCityStreamEvent | null {
   const eventLines = block
     .split(/\r?\n/)
@@ -369,10 +379,17 @@ export function useAiCityForecast({
           )
         : null;
     if (cachedPayload) {
-      setAiForecast({ payload: cachedPayload, status: "ready" });
-      return () => {
-        cancelled = true;
-      };
+      if (
+        cachedPayload.status === "ready" &&
+        !cachedPayload.degraded &&
+        cachedPayload.city_forecast
+      ) {
+        setAiForecast({ payload: cachedPayload, status: "ready" });
+        return () => {
+          cancelled = true;
+        };
+      }
+      removeCachedPayload(cacheKey);
     }
     const initialFallback = buildAiCityFallbackPayload({ detail, isEn, report });
     setAiForecast({