Show stale detail blocker while refreshing city data

frontend/hooks/useDashboardStore.tsx

@@ -788,11 +788,7 @@ export function DashboardStoreProvider({
       return;
     }
 
-    const cachedDetail = cityDetailsByName[cityName];
-    const needsDetailRefresh = hasSparseDetailCoverage(
-      cachedDetail,
-      cachedDetail?.local_date,
-    );
+    const needsDetailRefresh = true;
     setLoadingState((current) => ({ ...current, cityDetail: true }));
     const detailPromise = ensureCityDetail(cityName, needsDetailRefresh, "panel");
     void Promise.allSettled([summaryPromise, detailPromise])

frontend/hooks/useLeafletMap.ts

@@ -593,6 +593,13 @@ export function useLeafletMap({
     }
 
     async function maybeAutoShowNearbyStations() {
+      if (selectedCity && isLoadingDetail) {
+        autoNearbyCityRef.current = selectedCity;
+        clearNearbyRefreshTimer();
+        layer.clearLayers();
+        return;
+      }
+
       if (handlingAutoNearbyRef.current) {
         return;
       }
@@ -700,7 +707,7 @@ export function useLeafletMap({
       map.off("zoomend", syncVisibility);
       map.off("moveend", maybeAutoShowNearbyStations);
     };
-  }, [cityDetailsByName, selectedCity, selectedDetail, suspendMotion]);
+  }, [cityDetailsByName, selectedCity, selectedDetail, suspendMotion, isLoadingDetail]);
 
   // Centralized City Selection Zoom Effect
   // Higher level than selection: we only flyTo once the data is loaded (selectedDetail)