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/bootstrap/less/mixins/reset-text.less

@@ -0,0 +1,18 @@
+.reset-text() {
+  font-family: @font-family-base;
+  // We deliberately do NOT reset font-size.
+  font-style: normal;
+  font-weight: 400;
+  line-height: @line-height-base;
+  line-break: auto;
+  text-align: left; // Fallback for where `start` is not supported
+  text-align: start;
+  text-decoration: none;
+  text-shadow: none;
+  text-transform: none;
+  letter-spacing: normal;
+  word-break: normal;
+  word-spacing: normal;
+  word-wrap: normal;
+  white-space: normal;
+}