feat: enforce admin role checks in layouts and navbar navigation

shop/app/admin/layout.tsx

@@ -1,11 +1,28 @@
 import Link from 'next/link'
 import { LayoutDashboard, Package, Settings, Users, LogOut, LayoutGrid, ShoppingCart } from 'lucide-react'
 
-export default function AdminLayout({
+import { redirect } from 'next/navigation'
+import { createClient } from '@/lib/supabase/server'
+
+export default async function AdminLayout({
   children,
 }: {
   children: React.ReactNode
 }) {
+  const supabase = await createClient()
+  const { data: { user } } = await supabase.auth.getUser()
+  if (!user) redirect('/auth/login')
+
+  const { data: userData } = await supabase
+    .from('users')
+    .select('role')
+    .eq('id', user.id)
+    .single()
+
+  if (!userData || userData.role !== 'admin') {
+    redirect('/')
+  }
+
   return (
     <div className="flex min-h-screen bg-[#020617] text-white">
       {/* Sidebar */}