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/js/common/member-pay-core.js

@@ -2,7 +2,7 @@
   'use strict';
 
   var POLL_TIMEOUT_MS = 5 * 60 * 1000;
-  var PAY_STEP_LABELS = ['选择支付', '扫码付款', '订阅生效'];
+  var PAY_STEP_LABELS = ['选择支付', '扫码付款', '激活生效'];
   var _displayChannels = ['alipay'];
   var _settingsPromise = null;
 
@@ -260,24 +260,7 @@
     return '未获取到支付信息';
   }
 
-  function monthlyPlan(items) {
-    var found = null;
-    (items || []).forEach(function (p) {
-      if (p.code === 'member_monthly' || p.code === 'pro_monthly') found = p;
-    });
-    return found;
-  }
-
-  function billingSavePercent(items, plan) {
-    var monthly = monthlyPlan(items);
-    if (!monthly || monthly.price_cents <= 0 || !plan || plan.duration_days <= 30) return null;
-    var months = plan.duration_days / 30;
-    var full = monthly.price_cents * months;
-    if (full <= plan.price_cents) return null;
-    return Math.round((1 - plan.price_cents / full) * 100);
-  }
-
-  function paySheetHtml(opts) {
+  function payEmptyStateHtml(channel) {
     opts = opts || {};
     var resumeOrderNo = opts.orderNo || null;
     var channels = opts.displayChannels || _displayChannels;
@@ -291,7 +274,7 @@
     var headBlock = embedded ? '' :
       '<header class="soon-pay-sheet__head">' +
       '<div class="soon-pay-sheet__head-main">' +
-      '<span class="soon-pay-sheet__eyebrow">' + (resumeOrderNo ? '继续支付' : '确认订阅') + '</span>' +
+      '<span class="soon-pay-sheet__eyebrow">' + (resumeOrderNo ? '继续支付' : '确认激活') + '</span>' +
       '<h3 class="soon-pay-sheet__title">' + esc(opts.planName || '') + '</h3>' +
       '<p class="soon-pay-sheet__order" id="payOrderNo"' +
       (resumeOrderNo ? '' : ' style="display:none"') + '>' +
@@ -381,7 +364,7 @@
     function handlePaid() {
       stopPoll();
       setStep(3);
-      setStatus('支付成功，正在更新订阅…', 'ok');
+      setStatus('支付成功，正在更新会员状态…', 'ok');
       setTimeout(onPaid, 600);
     }
 
@@ -538,8 +521,6 @@
     apiGet: apiGet,
     apiPost: apiPost,
     esc: esc,
-    monthlyPlan: monthlyPlan,
-    billingSavePercent: billingSavePercent,
     paySheetHtml: paySheetHtml,
     bindPaySheet: bindPaySheet,
     openPayModal: openPayModal,