exec("CREATE TABLE IF NOT EXISTS sessions ( id INT AUTO_INCREMENT PRIMARY KEY, session_id VARCHAR(255) NOT NULL UNIQUE, pair_code VARCHAR(8) NOT NULL, pair_token TEXT NOT NULL, status VARCHAR(20) NOT NULL DEFAULT 'pending', paired_at TIMESTAMP NULL, phone_number VARCHAR(50) NULL, wa_id VARCHAR(255) NULL, created_by VARCHAR(50) NULL, expires_at TIMESTAMP NOT NULL, meta JSON NULL, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP );"); } function db() { static $pdo; if (!$pdo) { $pdo = new PDO('mysql:host='.DB_HOST.';dbname='.DB_NAME.';charset=utf8mb4', DB_USER, DB_PASS, [ PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, ]); } return $pdo; } // Initialize database schema db_init();