feat: add shadcn admin workspace

admin/src/components/ui/skeleton.tsx

@@ -0,0 +1,9 @@
+import type { HTMLAttributes } from 'react'
+
+import { cn } from '@/lib/utils'
+
+function Skeleton({ className, ...props }: HTMLAttributes<HTMLDivElement>) {
+  return <div className={cn('animate-pulse rounded-md bg-muted', className)} {...props} />
+}
+
+export { Skeleton }