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/fastadmin-dragsort/bower.json

@@ -0,0 +1,24 @@
+{
+  "name": "dragsort",
+  "version": "0.5.2",
+  "authors": [
+    "Michael McDonald"
+  ],
+  "description": "A javascript file that provides the ability to sort lists using drag and drop.",
+  "main": "jquery.dragsort.js",
+  "keywords": [
+    "javascript",
+    "sort",
+    "jquery"
+  ],
+  "license": "http://dragsort.codeplex.com/license",
+  "homepage": "http://dragsort.codeplex.com/",
+  "ignore": [
+    "**/.*",
+    "bower_components",
+    "examples"
+  ],
+  "dependencies": {
+    "jquery": ">=1.6.0 <3.0.0"
+  }
+}