/**
 * Return the current week of year for the specified IANA timeZone.
 *
 * - Uses Temporal.Now.zonedDateTimeISO to get the current time.
 * - Uses Temporal.PlainDate.weekOfYear for ISO week number.
 * - Validation is performed on the timezone.
 *
 * @param ianaTimezone IANA timeZone identifier
 * @returns current week number (1-53) or null on invalid input
 *
 * @example getZonedWeekOfYear("America/New_York") // 9
 * @example getZonedWeekOfYear("invalid") // null
 */
export declare function getZonedWeekOfYear(ianaTimezone: string): number | null;