사용자 로그인, 가입 처리

src/app/editor/page.tsx

@@ -3,6 +3,7 @@
 import type { CSSProperties, ReactNode } from "react";
 import { Fragment, useEffect, useState } from "react";
 import Link from "next/link";
+import { useRouter } from "next/navigation";
 import { FilePlus2, Trash2, Eye, Pencil, ListChecks, Undo2, Redo2 } from "lucide-react";
 import {
   DndContext,
@@ -70,6 +71,7 @@ import { PropertiesSidebar } from "./panels/PropertiesSidebar";
 import { EditorCanvas } from "./EditorCanvas";
 
 export default function EditorPage() {
+  const router = useRouter();
   const blocks = useEditorStore((state) => state.blocks);
   const selectedBlockId = useEditorStore((state) => state.selectedBlockId);
   const selectedListItemId = useEditorStore((state) => (state as any).selectedListItemId as string | null | undefined);
@@ -138,6 +140,27 @@ export default function EditorPage() {
   const canUndo = historyLength > 0;
   const canRedo = futureLength > 0;
 
+  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]);
+
   const [menuOpen, setMenuOpen] = useState(false);
   const [activeModal, setActiveModal] = useState<"project" | "json" | null>(null);
 
@@ -286,6 +309,17 @@ export default function EditorPage() {
       });
 
       if (!response.ok) {
+        if (response.status === 409) {
+          try {
+            const data = await response.json();
+            if (data && typeof (data as any).message === "string") {
+              setProjectMessage((data as any).message as string);
+              return;
+            }
+          } catch {
+          }
+        }
+
         setProjectMessage("프로젝트 저장에 실패했습니다.");
         return;
       }