reset_admin.php usage:
1. Upload this project (or place this file) to your site root where config/db.php is accessible.
2. Open in browser: https://your-site/reset_admin.php
3. It will update password for username 'admin' if exists, or create a new 'admin' user with password 'Admin@1234'.
4. Immediately DELETE reset_admin.php after use for security.
