[DP-421] 마이페이지 로그인 가드 구현

app/(main)/my-page/layout.tsx

@@ -0,0 +1,33 @@
+"use client";
+
+import { useEffect } from "react";
+import { useRouter, usePathname } from "next/navigation";
+import { useAuthStore } from "@/store/auth.store";
+import { useHydrated } from "@/lib/hooks/useHydrated";
+
+export default function MyPageLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  const isAuthenticated = useAuthStore((s) => s.isAuthenticated);
+  const isInitialized = useAuthStore((s) => s.isInitialized);
+  const mounted = useHydrated();
+  const router = useRouter();
+  const pathname = usePathname();
+
+  const isSubPage = pathname !== "/my-page";
+
+  useEffect(() => {
+    if (mounted && isInitialized && !isAuthenticated && isSubPage) {
+      router.replace("/my-page");
+    }
+  }, [mounted, isInitialized, isAuthenticated, isSubPage, router]);
+
+  if (!mounted || !isInitialized) return null;
+
+  // 하위 페이지는 미인증 시 리다이렉트 대기 중 아무것도 표시 안 함
+  if (!isAuthenticated && isSubPage) return null;
+
+  return <>{children}</>;
+}

app/(main)/my-page/page.tsx

@@ -1,5 +1,23 @@
+"use client";
+
+import { useAuthStore } from "@/store/auth.store";
+import { useHydrated } from "@/lib/hooks/useHydrated";
+import { LoginRequiredEmptyState } from "@/components/features/auth/LoginRequiredEmptyState";
 import MyPage from "@/components/features/my-page/MyPage";
 
 export default function Page() {
+  const isAuthenticated = useAuthStore((s) => s.isAuthenticated);
+  const isInitialized = useAuthStore((s) => s.isInitialized);
+  const mounted = useHydrated();
+
+  if (!mounted || !isInitialized) return null;
+  if (!isAuthenticated)
+    return (
+      <LoginRequiredEmptyState
+        title="로그인이 필요합니다"
+        description="마이페이지는 로그인 후 이용할 수 있습니다."
+      />
+    );
+
   return <MyPage />;
 }