fix: SSO 로그인 성공 시 adminfront로의 리다이렉션 및 postMessage 흐름 강화 #243

userfront/lib/core/services/web_auth_integration_web.dart

@@ -3,8 +3,14 @@
 import 'dart:async';
 import 'dart:html' as html;
 import 'package:flutter/foundation.dart';
+import 'auth_token_store.dart';
 
 void implSendLoginSuccess(String token) {
+  var effectiveToken = token;
+  if (effectiveToken.isEmpty) {
+    effectiveToken = AuthTokenStore.getToken() ?? "";
+  }
+
   final uri = Uri.parse(html.window.location.href);
   final redirectUri = uri.queryParameters['redirect_uri'];
 
@@ -12,7 +18,7 @@ void implSendLoginSuccess(String token) {
     // Redirection flow
     final target = Uri.parse(redirectUri);
     final query = Map<String, String>.from(target.queryParameters);
-    query['token'] = token;
+    query['token'] = effectiveToken;
     final finalUri = target.replace(queryParameters: query);
     
     debugPrint('Redirecting to: ${finalUri.toString()}');
@@ -20,7 +26,7 @@ void implSendLoginSuccess(String token) {
     return;
   }
 
-  final message = {'type': 'LOGIN_SUCCESS', 'token': token};
+  final message = {'type': 'LOGIN_SUCCESS', 'token': effectiveToken};
   
   if (html.window.opener != null) {
     try {