feat: add enterprise app ui layer

frontend/src/app/layout/AppShell.tsx

@@ -1,7 +1,7 @@
 import type * as React from 'react'
 
-import { Sidebar } from './Sidebar'
-import { Topbar } from './Topbar'
+import { AppSidebar } from '@/components/app/AppSidebar'
+import { AppTopbar } from '@/components/app/AppTopbar'
 
 type AppShellProps = {
   children: React.ReactNode
@@ -10,9 +10,9 @@ type AppShellProps = {
 export function AppShell({ children }: AppShellProps) {
   return (
     <div className="min-h-screen bg-background text-foreground">
-      <Sidebar />
-      <div className="min-h-screen lg:pl-64">
-        <Topbar />
+      <AppSidebar />
+      <div className="min-h-screen lg:pl-72">
+        <AppTopbar />
         {children}
       </div>
     </div>