feat: add enterprise app ui layer

frontend/src/components/app/AppSection.tsx

@@ -0,0 +1,25 @@
+import type * as React from 'react'
+
+import { Card, CardContent, CardHeader } from '@/components/ui/card'
+
+type AppSectionProps = {
+  title: string
+  description?: string
+  action?: React.ReactNode
+  children: React.ReactNode
+}
+
+export function AppSection({ title, description, action, children }: AppSectionProps) {
+  return (
+    <Card>
+      <CardHeader className="flex flex-row items-start justify-between gap-3">
+        <div>
+          <h2 className="text-sm font-semibold text-foreground">{title}</h2>
+          {description ? <p className="mt-1 text-sm text-muted-foreground">{description}</p> : null}
+        </div>
+        {action}
+      </CardHeader>
+      <CardContent>{children}</CardContent>
+    </Card>
+  )
+}