refactor: Remove RedHat/CentOS support, focus on Ubuntu/Debian

BREAKING CHANGE: Removed RedHat/CentOS/Rocky Linux support to improve stability

- Remove all RedHat/CentOS-specific code and variables
- Consolidate Ubuntu/Debian variables into single debian-family.yml
- Simplify CI/CD pipeline (remove CentOS tests)
- Remove unstable multi-OS complexity
- Update documentation to reflect Ubuntu/Debian focus
- Streamline playbooks for better maintainability

This change makes the project more stable and maintainable by focusing
on the most common server distributions (Ubuntu/Debian) instead of
trying to support multiple OS families with different package managers
and configurations.

vars/debian-family.yml

@@ -0,0 +1,45 @@
+# Ubuntu/Debian family variables
+---
+# Package names for Ubuntu/Debian systems
+packages:
+  - nginx
+  - mysql-server
+  - php8.3-fpm
+  - php8.3-mysql
+  - php8.3-curl
+  - php8.3-gd
+  - php8.3-intl
+  - php8.3-mbstring
+  - php8.3-soap
+  - php8.3-xml
+  - php8.3-xmlrpc
+  - php8.3-zip
+  - python3-pymysql
+  - unzip
+
+# Service names
+mysql_service: mysql
+nginx_service: nginx
+php_fpm_service: php8.3-fpm
+
+# Package manager
+package_manager: apt
+
+# PHP paths
+php_fpm_config_path: /etc/php/8.3/fpm
+php_cli_config_path: /etc/php/8.3/cli
+php_fpm_pool_path: /etc/php/8.3/fpm/pool.d
+
+# Nginx paths
+nginx_config_path: /etc/nginx
+nginx_sites_available: /etc/nginx/sites-available
+nginx_sites_enabled: /etc/nginx/sites-enabled
+
+# MySQL paths
+mysql_config_path: /etc/mysql
+
+# Default PHP version
+php_version: "8.3"
+
+# System paths
+web_root: /var/www/html