feat: setup database-driven admin user management

app/admin/users/page.tsx

@@ -0,0 +1,13 @@
+import { getUsers } from "@/app/actions/users";
+import UsersClient from "./UsersClient";
+
+export default async function UsersPage() {
+  const users = await getUsers();
+
+  return (
+    <div className="max-w-4xl mx-auto w-full">
+      <h1 className="text-3xl font-bold font-serif mb-6 text-dark">Kullanıcı Yönetimi</h1>
+      <UsersClient initialUsers={users} />
+    </div>
+  );
+}