fix: change button type to submit in ChangeAPI component and update temperature unit logic in WeatherData component

frontend/src/components/ChangeAPI.tsx

@@ -64,7 +64,7 @@ const ChangeAPI: React.FC<Props> = ({ currentAPIKey, onClose }) => {
           />
         </div>
         <button
-          type="button"
+          type="submit"
           className="bg-gradient-to-r from-blue-600 to-blue-400 text-white font-bold px-6 py-3 rounded-xl shadow-lg hover:from-blue-700 hover:to-blue-500 transition-all"
           onClick={handleUpdate}
         >

frontend/src/components/WeatherData.tsx

@@ -24,7 +24,9 @@ const WeatherData: React.FC = () => {
             ? "°C"
             : localStorage.getItem("unit") === "imperial"
             ? "°F"
-            : "K"}
+            : localStorage.getItem("unit") === "standard"
+            ? "K"
+            : "°C"}
         </p>
         <p className="flex items-center justify-center gap-2">
           {weatherData?.sys?.country && (