SSO 로그인 방식을 팝업 기반으로 변경

devfront/src/features/auth/AuthCallbackPage.tsx

@@ -1,12 +1,19 @@
 import { useEffect } from "react";
 import { useAuth } from "react-oidc-context";
 import { useNavigate } from "react-router-dom";
+import { userManager } from "../../lib/auth";
 
 export default function AuthCallbackPage() {
   const auth = useAuth();
   const navigate = useNavigate();
 
   useEffect(() => {
+    // 팝업으로 열린 경우 signinPopupCallback 처리
+    if (window.opener) {
+      userManager.signinPopupCallback();
+      return;
+    }
+
     if (auth.isAuthenticated) {
       navigate("/", { replace: true });
     } else if (auth.error) {