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

public/assets/libs/art-template/node/template.js

@@ -0,0 +1,9 @@
+/*!
+ * artTemplate[NodeJS]
+ * https://github.com/aui/artTemplate
+ * Released under the MIT, BSD, and GPL Licenses
+ */
+
+var node = require('./_node.js');
+var template = require('../dist/template-debug.js');
+module.exports = node(template);