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/nuget/bootstrap-select.nuspec

@@ -0,0 +1,22 @@
+<?xml version="1.0"?>
+<package xmlns="http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd">
+    <metadata>
+        <id>bootstrap-select</id>
+        <version>1.11.2</version>
+        <title>bootstrap-select</title>
+        <authors>Silvio Moreto,Ana Carolina,caseyjhol,Matt Bryson,and t0xicCode.</authors>
+        <owners>Silvio Moreto</owners>
+        <projectUrl>https://github.com/silviomoreto/bootstrap-select</projectUrl>
+        <description>Bootstrap-select is a jQuery plugin that utilizes Bootstrap's dropdown.js to style and bring additional functionality to standard select elements.</description>
+        <tags>bootstrap dropdown select</tags>
+        <requireLicenseAcceptance>false</requireLicenseAcceptance>
+        <dependencies>
+            <dependency id="jQuery" version="1.8.0" />
+        </dependencies>
+    </metadata>
+    <files>
+        <file src="dist\js\bootstrap-select*.*" target="content\Scripts" />
+        <file src="dist\js\i18n\*.*" target="content\Scripts\i18n" />
+        <file src="dist\css\*.*" target="content\Content" />
+    </files>
+</package>