永久会员与模板库后台化：预览门控、轻量首页与 Admin CRUD

- 会员改为永久激活方案；云端文件不再拦截非会员；预览弹窗内导出/打印才校验
- 首页最近文件支持本地记录，登录后与云端合并；移除独立会员页与订阅页
- 模板库入库管理：soon_templates 表、Admin 上传 CRUD、/templates 轻量列表与按需下载

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

frontend-web/pages/admin/assets/js/views/orders.js

@@ -202,11 +202,11 @@
 
       var subHtml;
       if (sub) {
-        subHtml = Ui().detailRow('订阅状态', I().badgeStatus(sub.status)) +
+        subHtml = Ui().detailRow('会员状态', I().badgeStatus(sub.status)) +
           Ui().detailRow('开始', I().esc(I().formatDateTime(sub.started_at))) +
           Ui().detailRow('到期', I().esc(I().formatDateTime(sub.expires_at)));
       } else {
-        subHtml = '<p class="soon-admin-detail-empty">无关联订阅</p>';
+        subHtml = '<p class="soon-admin-detail-empty">无关联会员记录</p>';
       }
 
       var drawerActions = rowActions(o).replace(/<button[^>]*order-detail-btn[^>]*>[\s\S]*?<\/button>/, '');