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>

backend-web/schema.sql

@@ -48,12 +48,14 @@ CREATE TABLE IF NOT EXISTS `plans` (
 INSERT INTO `plans` (`code`,`name`,`description`,`price_cents`,`quota_mb`,`max_files`,`duration_days`,`features`,`sort_order`,`is_recommended`,`is_active`) VALUES
   ('free','免费版','免费体验设计与编辑',0,2048,200,0,
    '["设计与编辑工具免费使用"]',0,0,1),
+  ('member_lifetime','永久会员','一次激活，永久使用预览交付能力',100,2048,200,0,
+   '["高清预览","成品打印","云端保存","导出设计文件","永久有效"]',10,1,1),
   ('member_monthly','月度订阅','按月灵活使用，随时续订',1999,2048,200,30,
-   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 个月"]',10,1,1),
+   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 个月"]',20,0,0),
   ('member_quarterly','季度订阅','连续三个月，更省心',5299,2048,200,90,
-   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 季"]',15,0,1),
+   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 季"]',25,0,0),
   ('member_yearly','年度订阅','全年畅享，性价比更高',19999,2048,200,365,
-   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 年"]',20,0,1)
+   '["高清预览","成品打印","云端保存","导出设计文件","订阅周期：1 年"]',30,0,0)
 ON DUPLICATE KEY UPDATE
   name=VALUES(name),
   description=VALUES(description),
@@ -63,7 +65,8 @@ ON DUPLICATE KEY UPDATE
   duration_days=VALUES(duration_days),
   features=VALUES(features),
   sort_order=VALUES(sort_order),
-  is_recommended=VALUES(is_recommended);
+  is_recommended=VALUES(is_recommended),
+  is_active=VALUES(is_active);
 
 CREATE TABLE IF NOT EXISTS `subscriptions` (
   `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
@@ -114,6 +117,20 @@ CREATE TABLE IF NOT EXISTS `audit_logs` (
   KEY `admin` (`admin_id`, `created_at`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
+CREATE TABLE IF NOT EXISTS `soon_templates` (
+  `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
+  `name` VARCHAR(120) NOT NULL,
+  `type` TINYINT UNSIGNED NOT NULL DEFAULT 1,
+  `thumb` MEDIUMTEXT DEFAULT NULL,
+  `file_size` INT UNSIGNED NOT NULL DEFAULT 0,
+  `sort_order` INT NOT NULL DEFAULT 0,
+  `is_active` TINYINT(1) NOT NULL DEFAULT 1,
+  `created_at` DATETIME NOT NULL,
+  `updated_at` DATETIME NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `active_sort` (`is_active`, `sort_order`, `id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
 CREATE TABLE IF NOT EXISTS `settings` (
   `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
   `key` VARCHAR(120) NOT NULL,