add client/admin pages, show info and created admin api and server actions

app/api/admin/route.ts

@@ -0,0 +1,10 @@
+import { NextResponse } from 'next/server'
+import { currentRole } from '@/lib/auth'
+import { UserRole } from '@prisma/client'
+
+export async function GET () {
+  const role = await currentRole()
+  const status: number = role === UserRole.ADMIN ? 200 : 403
+
+  return new NextResponse(null, { status })
+}