fix: handle error response during update check in UpdateNotification component

src/app/components/update-notification/UpdateNotification.tsx

@@ -61,7 +61,15 @@ export function UpdateNotification() {
     try {
       const result = await (window as any).electron.updater.checkForUpdates();
       console.log('Update check result:', result);
-      // If no update found, show feedback
+      
+      // Handle error response (including dev mode error)
+      if (!result.success) {
+        console.warn('Update check failed:', result.error);
+        setChecking(false);
+        return;
+      }
+      
+      // If no update found, show feedback briefly
       setTimeout(() => {
         if (!updateAvailable) {
           setChecking(false);