feat: 后端全量更新 - 含所有本次需求

- Contract.php: 返回合约账户余额(balance_contract)
- My.php: 地址管理增加BTC/ETH
- AppContract.php: 一键平仓(closeall)
- AppProxy.php: 代理专属注册链接 + 分级权限(L1/L2)
- site.php: 手续费减半(0.018→0.009)
- agent_permission_setup.sql: 代理权限SQL
- crypto_news_crawler.py: 新闻自动采集脚本

application/admin/command/Addon/stubs/config.stub

@@ -0,0 +1,40 @@
+<?php
+
+return [
+    [
+        //配置唯一标识
+        'name'    => 'usernmae',
+        //显示的标题
+        'title'   => '用户名',
+        //类型
+        'type'    => 'string',
+        //数据字典
+        'content' => [
+        ],
+        //值
+        'value'   => '',
+        //验证规则 
+        'rule'    => 'required',
+        //错误消息
+        'msg'     => '',
+        //提示消息
+        'tip'     => '',
+        //成功消息
+        'ok'      => '',
+        //扩展信息
+        'extend'  => ''
+    ],
+    [
+        'name'    => 'password',
+        'title'   => '密码',
+        'type'    => 'string',
+        'content' => [
+        ],
+        'value'   => '',
+        'rule'    => 'required',
+        'msg'     => '',
+        'tip'     => '',
+        'ok'      => '',
+        'extend'  => ''
+    ],
+];