Refactor AppRouter to use dynamic base name from environment variable

frontend/src/components/AppRouter.tsx

@@ -42,9 +42,16 @@ const PublicRoute = ({ children }: { children: React.ReactElement }): React.Reac
   );
 };
 
+const baseName = (() => {
+  if (!env.VITE_APP_BASE_URL) return "";
+  let baseUrl = env.VITE_APP_BASE_URL.endsWith("/") ? env.VITE_APP_BASE_URL.slice(0, -1) : env.VITE_APP_BASE_URL;
+  baseUrl = baseUrl.startsWith("/") ? baseUrl : `/${baseUrl}`;
+  return baseUrl;
+})();
+
 const AppRouter: React.FC = () => {
   return (
-    <BrowserRouter basename={env.VITE_APP_BASE_URL || ""}>
+    <BrowserRouter basename={baseName}>
       <Routes>
         <Route path="/" element={<Navigate to="/dashboard" />} />
         <Route