CREATE TABLE activity_logs (
    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    business_id INT UNSIGNED NOT NULL,
    user_id INT UNSIGNED NOT NULL,
    action VARCHAR(80) NOT NULL,
    entity_type VARCHAR(50) NOT NULL,
    entity_id INT UNSIGNED DEFAULT NULL,
    metadata JSON DEFAULT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    CONSTRAINT fk_logs_business FOREIGN KEY (business_id) REFERENCES businesses(id) ON DELETE CASCADE,
    CONSTRAINT fk_logs_user FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    INDEX idx_logs_business (business_id, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;