优化支付宝支付流程与 Web 端体验

- 支付宝新窗口跳转，轮询与手动刷新增加加载反馈
- 支付回跳先校验订单状态，避免未付款误报成功
- 门户登录回调统一，云文件打开加载与版本冲突同步
- 精简本地 start.bat 与 README 说明

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend-web/pages/design2.web.html

@@ -689,11 +689,6 @@
     <script>
       if (window.SoonPortalTopbar) SoonPortalTopbar.mount('#portal-topbar', { variant: 'design' });
       if (window.soonPortalAuth) soonPortalAuth.init({ logoutReload: false });
-      if (window.soonLoadMembership) {
-        window.soonLoadMembership().then(function () {
-          if (window.soonRefreshPortalIdentity) window.soonRefreshPortalIdentity();
-        });
-      }
     </script>
 </body>