fix：商城登录互通问题

lib/features/auth/presentation/login_page.dart

@@ -47,11 +47,19 @@ class LoginPage extends HookConsumerWidget {
     Future<void> returnAfterLogin() async {
       final target = next?.trim();
       final router = GoRouter.of(context);
-      if (target == null || target.isEmpty) {
-        router.go(AppRoutes.profile);
+      if (target != null && target.isNotEmpty) {
+        router.go(target);
         return;
       }
-      router.go(target);
+      // The mall opens this page with no `next`. Pop back to its resident
+      // WebView so the auth-state listener can deliver `enterWebMall` after
+      // the app-mall token has been issued. Replacing the route here disposes
+      // that WebView before the asynchronous hand-off can finish.
+      if (context.canPop()) {
+        context.pop();
+      } else {
+        router.go(AppRoutes.profile);
+      }
     }
 
     void startCountdown() {