[FEAT] 페이지 접근 인증 모듈 추가 (#123)

* feat: add auth module

* feat: add auth module to admin layout

src/app/(admin)/layout.tsx

@@ -1,13 +1,16 @@
 import { Metadata } from "next";
 import classes from "./layout.module.css";
 import { AdminSidebar } from "@/components/pages/AdminSidebar";
+import { AuthModule } from "@/components/common/Auth/AuthModule";
 
 export const metadata: Metadata = {
   title: "S-TOP 기술교류회 관리자",
   description: "S-TOP 기술교류회 관리자",
 };
 
-export default function AdminLayout({ children }: { children: React.ReactNode }) {
+export default async function AdminLayout({ children }: { children: React.ReactNode }) {
+  await AuthModule({ userType: ["ADMIN"] });
+
   return (
     <section className={classes.container}>
       <AdminSidebar />

src/components/common/Auth/AuthModule.ts

@@ -0,0 +1,30 @@
+"use server";
+
+import { JWT_COOKIE_NAME } from "@/constants/Auth";
+import { redirect } from "next/navigation";
+import { cookies } from "next/headers";
+import { jwtDecode, JwtPayload } from "jwt-decode";
+import { Role } from "@/types/user";
+
+export interface CustomJwtPayload extends JwtPayload {
+  userType: Role;
+}
+
+interface Props {
+  userType: Role[];
+}
+
+export async function AuthModule({ userType }: Props): Promise<{ token: string }> {
+  const token = cookies().get(JWT_COOKIE_NAME)?.value;
+
+  if (!token) {
+    redirect("/login");
+  }
+
+  const decoded = jwtDecode<CustomJwtPayload>(token);
+  if (!userType.includes(decoded.userType)) {
+    redirect("/");
+  }
+
+  return { token };
+}