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/docs/mkdocs.yml

@@ -0,0 +1,17 @@
+site_name: bootstrap-select
+site_description: Bootstrap-select is a jQuery plugin that utilizes Bootstrap's dropdown.js to style and bring additional functionality to standard select elements.
+repo_url: https://github.com/silviomoreto/bootstrap-select
+theme: bootstrap
+theme_dir: custom_theme
+extra_css:
+- css/custom.css
+- dist/css/bootstrap-select.min.css
+extra_javascript:
+- dist/js/bootstrap-select.min.js
+pages:
+- Bootstrap-select: index.md
+- Examples: examples.md
+- Options: options.md
+- Methods: methods.md
+extra:
+    version: 1.11.2