修复订阅授权返回后生成中断

生成动作先进入拼图进度页并立即发起生成

订阅授权改为非阻塞尝试，避免闪回卡住提交

移除订阅结果回写 web-view URL 导致回首页的逻辑

更新小程序订阅消息授权与发送边界文档

miniprogram/pages/subscribe-message/index.shared.js

@@ -57,14 +57,6 @@ function createSubscribeMessagePage(pageContext, options = {}) {
       const page = pageContext ?? this;
       page.requestId = String(query.requestId || '');
       page.hasNotifiedSubscribeResult = false;
-      page.autoRequest = query.autoRequest === '1' || query.autoRequest === true;
-      if (page.autoRequest) {
-        setTimeout(() => {
-          if (!page.hasNotifiedSubscribeResult) {
-            this.requestSubscribe.call(page);
-          }
-        }, 0);
-      }
     },
 
     notifyResult(status, reason) {