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-select/bower.json

@@ -0,0 +1,31 @@
+{
+  "name": "bootstrap-select",
+  "main": [
+    "less/bootstrap-select.less",
+    "dist/css/bootstrap-select.css",
+    "dist/js/bootstrap-select.js"
+  ],
+  "homepage": "http://silviomoreto.github.io/bootstrap-select",
+  "authors": [
+    "silviomoreto"
+  ],
+  "keywords": [
+    "form",
+    "bootstrap",
+    "select",
+    "replacement"
+  ],
+  "dependencies": {
+    "jquery": ">=1.8"
+  },
+  "license": "MIT",
+  "ignore": [
+    ".gitignore",
+    "CONTRIBUTING.md",
+    "Gruntfile.js",
+    "README.md",
+    "composer.json",
+    "package.json",
+    "test.html"
+  ]
+}