Make city clicks update homepage focus

frontend/components/dashboard/CitySidebar.tsx

@@ -251,7 +251,7 @@ export function CitySidebar() {
                       className={clsx("city-item", isActive && "active")}
                       onClick={() =>
                         startTransition(() => {
-                          void store.selectCity(city.name);
+                          void store.focusCity(city.name);
                         })
                       }
                     >

frontend/components/dashboard/MapCanvas.tsx

@@ -16,7 +16,7 @@ export function MapCanvas() {
     onMapInteractionChange: store.setMapInteractionActive,
     onRegisterStopMotion: store.registerMapStopMotion,
     onSelectCity: (cityName) => {
-      void store.selectCity(cityName);
+      void store.focusCity(cityName);
     },
     selectedCity: store.selectedCity,
     selectedDetail: store.selectedDetail,

frontend/components/dashboard/PolyWeatherDashboard.tsx

@@ -280,7 +280,7 @@ function OpportunityStrip({ snapshots }: { snapshots: CitySnapshot[] }) {
               key={city.name}
               type="button"
               className="opportunity-card"
-              onClick={() => void store.selectCity(city.name)}
+              onClick={() => void store.focusCity(city.name)}
             >
               <span className={clsx("opportunity-risk-dot", String(tier || "other"))} />
               <span className="opportunity-city">{city.display_name}</span>

frontend/hooks/useDashboardStore.tsx

@@ -41,6 +41,7 @@ interface DashboardStoreValue extends DashboardState {
     force?: boolean,
     depth?: "panel" | "nearby" | "full",
   ) => Promise<CityDetail>;
+  focusCity: (cityName: string) => Promise<void>;
   forecastModalMode: ForecastModalMode | null;
   futureModalDate: string | null;
   loadCities: () => Promise<void>;
@@ -804,6 +805,15 @@ export function DashboardStoreProvider({
       });
   };
 
+  const focusCity = async (cityName: string) => {
+    setSelectedCity(cityName);
+    setIsPanelOpen(false);
+    setSelectedForecastDate(null);
+    setFutureModalDate(null);
+    setForecastModalMode(null);
+    void ensureCitySummary(cityName).catch(() => null);
+  };
+
   useEffect(() => {
     if (typeof window === "undefined") return;
     if (selectedCity) {
@@ -1016,6 +1026,7 @@ export function DashboardStoreProvider({
         setIsPanelOpen(false);
       },
       ensureCityDetail,
+      focusCity,
       forecastModalMode,
       futureModalDate,
       historyState,