regroup backend and frontend in app folder

app/frontend/src/App.tsx

@@ -0,0 +1,37 @@
+import { Toaster } from "@/components/ui/toaster";
+import { Toaster as Sonner } from "@/components/ui/sonner";
+import { TooltipProvider } from "@/components/ui/tooltip";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { BrowserRouter, Routes, Route } from "react-router-dom";
+import Index from "./pages/Index";
+import Admin from "./pages/Admin";
+import Login from "./pages/Login";
+import Users from "./pages/Users";
+import ApiKeys from "./pages/ApiKeys";
+import ProtectedRoute from "./components/ProtectedRoute"
+import NotFound from "./pages/NotFound";
+
+const queryClient = new QueryClient();
+
+const App = () => (
+  <QueryClientProvider client={queryClient}>
+    <TooltipProvider>
+      <Toaster />
+      <Sonner />
+      <BrowserRouter>
+        <Routes>
+          <Route path="/" element={<Index />} />
+          <Route path="/login" element={<Login />} />
+          <Route path="/admin" element={
+                  <Admin />
+          } />
+          <Route path="/admin/users" element={<Users />} />
+          <Route path="/admin/api-keys" element={<ApiKeys />} />
+          <Route path="*" element={<NotFound />} />
+        </Routes>
+      </BrowserRouter>
+    </TooltipProvider>
+  </QueryClientProvider>
+);
+
+export default App;