前端配置迁至 config/local.js，完善支付、模板库与部署脚本

- 页面直接引用 local.js 设置 SOON_DEPLOY_CONFIG，移除 deploy-config
- Docker sync-config 生成 local.js；更新 README 与 agent-core 说明
- 模板库自动扫描 .soon；新增后端部署/种子/排查脚本
- 完善支付配置、订阅弹窗与后台支付管理页

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

backend-web/public/admin.php

@@ -65,6 +65,7 @@ Router::post('/api/admin/settings/batch', [SettingsController::class, 'setBatch'
 Router::get('/api/admin/audits', [AuditsController::class, 'list']);
 
 Router::post('/api/admin/payment/upload', [PaymentController::class, 'upload']);
+Router::post('/api/admin/payment/config', [PaymentController::class, 'saveConfig']);
 Router::get('/api/admin/payment/status', [PaymentController::class, 'status']);
 
 if (str_starts_with($path, '/api/admin/')) {