CREATE TABLE IF NOT EXISTS audit_log (
    id INT AUTO_INCREMENT PRIMARY KEY,
    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    user VARCHAR(255) NOT NULL,
    action VARCHAR(255) NOT NULL,
    details JSON,
    INDEX (timestamp),
    INDEX (user),
    INDEX (action)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;