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/.bower.json

@@ -0,0 +1,14 @@
+{
+  "name": "art-template",
+  "homepage": "https://github.com/aui/artTemplate",
+  "version": "3.1.3",
+  "_release": "3.1.3",
+  "_resolution": {
+    "type": "version",
+    "tag": "v3.1.3",
+    "commit": "b1085f546f6d3abbf74d10a5f69d24a63e932e86"
+  },
+  "_source": "https://github.com/aui/artTemplate.git",
+  "_target": "~3.1.3",
+  "_originalSource": "art-template"
+}