Update Docker configuration and plugin versions - Upgrade MariaDB from 10.6 to 11 with auto-upgrade support - Add WordPress debug environment variable to FPM container - Update PHP-FPM Dockerfile base image - Update Include Mastodon Feed plugin with bug fixes and improvements - Update Portfolio plugin (v2.58) with latest translations and demo data enhancements - Remove old README.md from Mastodon Feed plugin 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>

<?php
/**
 * Custom background script.
 *
 * This file is deprecated, use 'wp-admin/includes/class-custom-background.php' instead.
 *
 * @deprecated 5.3.0
 * @package WordPress
 * @subpackage Administration
 */

// Don't load directly.
if ( ! defined( 'ABSPATH' ) ) {
	die( '-1' );
}

_deprecated_file( basename( __FILE__ ), '5.3.0', 'wp-admin/includes/class-custom-background.php' );

/** Custom_Background class */
require_once ABSPATH . 'wp-admin/includes/class-custom-background.php';