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/index.web.html

@@ -157,13 +157,11 @@
 
   <script>
     if (window.SoonPortalTopbar) SoonPortalTopbar.mount('#portal-topbar', { active: 'home' });
-    soonPortalAuth.init();
-    if (window.soonLoadMembership) {
-      window.soonLoadMembership().then(function () {
-        if (window.soonRefreshPortalIdentity) window.soonRefreshPortalIdentity();
+    soonPortalAuth.init({
+      onAuthed: function () {
         if (window.soonReloadRecentFiles) window.soonReloadRecentFiles();
-      });
-    }
+      }
+    });
   </script>
 
 </body>