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-table/composer.json

@@ -0,0 +1,17 @@
+{
+    "name": "karsonzhang/fastadmin-bootstraptable",
+    "description": "An extended Bootstrap table with radio, checkbox, sort, pagination and other features.",
+    "keywords": ["bootstrap","table","tablesort","pagination"],
+    "type": "component",
+    "homepage": "https://github.com/karsonzhang/fastadmin-bootstraptable",
+    "license": "MIT",
+    "require": {
+        "twitter/bootstrap": ">=3.3.0"
+    },
+    "authors": [
+        {
+            "name": "wenzhixin2010",
+            "email": "wenzhixin2010@gmail.com"
+        }
+    ]
+}