CREATE TABLE IF NOT EXISTS `users` (
  `id` INT AUTO_INCREMENT PRIMARY KEY,
  `email` VARCHAR(255) NOT NULL UNIQUE,
  `password_hash` VARCHAR(255) NOT NULL,
  `role` ENUM('admin', 'finance', 'support', 'client', 'supplier') NOT NULL,
  `is_active` BOOLEAN NOT NULL DEFAULT TRUE,
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);