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/GoJS-master/samples/images/sort.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generated by IcoMoon.io -->
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="16" height="16" viewBox="0 0 16 16">
+<path fill="#000000" d="M5 12v-12h-2v12h-2.5l3.5 3.5 3.5-3.5h-2.5z"></path>
+<path fill="#000000" d="M7 9h9v2h-9v-2z"></path>
+<path fill="#000000" d="M7 6h7v2h-7v-2z"></path>
+<path fill="#000000" d="M7 3h5v2h-5v-2z"></path>
+<path fill="#000000" d="M7 0h3v2h-3v-2z"></path>
+</svg>