/**
 * Parse a duration to milliseconds. Accepts:
 *   - A positive integer number of seconds.
 *   - A duration string with a unit suffix: `'500ms'`, `'30s'`,
 *     `'15m'`, `'1h'`, `'7d'`, `'2w'`.
 *
 * @param {string | number} input
 * @param {string} name       Field label for the error message.
 * @returns {number}          Duration in milliseconds.
 */
export function parseDuration(input: string | number, name?: string): number;