사용자 로그인, 가입 처리

src/app/preview/page.tsx

@@ -3,15 +3,38 @@
 import type { CSSProperties } from "react";
 import { useEffect } from "react";
 import Link from "next/link";
+import { useRouter } from "next/navigation";
 import { useEditorStore } from "@/features/editor/state/editorStore";
 import { PublicPageRenderer } from "@/features/editor/components/PublicPageRenderer";
 
 export default function PreviewPage() {
+  const router = useRouter();
   const blocks = useEditorStore((state) => state.blocks);
   const projectConfig = useEditorStore((state) => (state as any).projectConfig);
   const replaceBlocks = useEditorStore((state) => state.replaceBlocks);
   const updateProjectConfig = useEditorStore((state) => state.updateProjectConfig);
 
+  useEffect(() => {
+    let cancelled = false;
+
+    const checkAuth = async () => {
+      try {
+        const res = await fetch("/api/auth/me");
+        if (!res.ok && res.status === 401 && !cancelled) {
+          router.push("/login");
+        }
+      } catch {
+        // 네트워크 오류 등은 일단 무시하고, 페이지 접근을 막지 않는다.
+      }
+    };
+
+    void checkAuth();
+
+    return () => {
+      cancelled = true;
+    };
+  }, [router]);
+
   useEffect(() => {
     if (typeof window === "undefined") return;