fix: docker packages and IP parsing for 127.0.0.1

kittyurl-frontend/src/App.tsx

@@ -11,6 +11,13 @@ export type View = 'home' | 'login' | 'history' | 'jump-game' | 'flappy-game';
 
 const getSubdomain = () => {
     const hostname = window.location.hostname;
+    // Handle localhost and 127.0.0.1 cases.
+    // For more advanced cases (like bare IP hosting)
+    // a regex may be necessary.
+    if (hostname === 'localhost' || hostname === '127.0.0.1') {
+        return null;
+    }
+    
     const parts = hostname.split('.');
     if (parts.length <= 2) return null;
     return parts[0];