Add k3s cluster expansion documentation and scripts

- Complete expansion guide for 2/4/6 node scenarios
- Quick join scripts for worker and master nodes
- Health check and diagnostic scripts
- Quick reference card for common operations

php-test/config.php

@@ -0,0 +1,11 @@
+<?php
+// 数据库配置
+define('DB_HOST', 'localhost');
+define('DB_NAME', 'test_db');
+define('DB_USER', 'root');
+define('DB_PASS', '');
+define('DB_CHARSET', 'utf8mb4');
+
+// 错误报告设置（开发环境）
+error_reporting(E_ALL);
+ini_set('display_errors', 1);