feat: add LoadingBar component with loading animation

apps/frontend/src/components/layout/Layout.tsx

@@ -2,12 +2,14 @@ import { useState } from "react";
 import { Outlet } from "@tanstack/react-router";
 import { Header } from "./Header";
 import { Sidebar } from "./Sidebar";
+import { LoadingBar } from "@/components/ui/loading-bar";
 
 export function Layout() {
   const [sidebarOpen, setSidebarOpen] = useState(false);
 
   return (
     <div className="flex min-h-screen">
+      <LoadingBar />
       <Sidebar open={sidebarOpen} onClose={() => setSidebarOpen(false)} />
       <div className="flex flex-1 flex-col">
         <Header onMenuClick={() => setSidebarOpen(true)} />