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/Sortable/.jshintrc

@@ -0,0 +1,25 @@
+{
+	"strict": false,
+	"newcap": false,
+	"node": true,
+	"expr": true,
+	"supernew": true,
+	"laxbreak": true,
+	"esversion": 9,
+	"white": true,
+	"globals": {
+		"define": true,
+		"test": true,
+		"expect": true,
+		"module": true,
+		"asyncTest": true,
+		"start": true,
+		"ok": true,
+		"equal": true,
+		"notEqual": true,
+		"deepEqual": true,
+		"window": true,
+		"document": true,
+		"performance": true
+	}
+}