/**
 * Gets, sets, or removes an attribute on a DOM element.
 * This is a type-safe wrapper around the native DOM attribute methods.
 *
 * @param element - The DOM element to operate on.
 * @param name - The name of the attribute to get, set, or remove.
 * @param value - The value to set for the attribute. If null, the attribute will be removed.
 * @returns The element's attribute value when getting, or the element itself when setting/removing.
 * @throws {TypeError} If element is not a valid DOM element or name is not a string.
 * @example
 * // Get an attribute
 * const style = attr(element, 'style');
 *
 * // Set an attribute
 * attr(element, 'id', 'new-element-id');
 *
 * // Remove an attribute
 * attr(element, 'data-temp', null);
 */
export declare function attr(element: Element, name: string, value?: string | null): string | null | Element;