/**
 * Return an array of ISO PlainDate strings for every day in the given year-month.
 *
 * - Generates array of dates for the specified month.
 * - Validates input matches the year-month format exactly.
 * - Returns [] for invalid input.
 *
 * @param month ISO PlainYearMonth string (YYYY-MM)
 * @returns array of ISO PlainDate strings for each day in the month
 *
 * @example mapDaysInMonth("2024-02") // ["2024-02-01", "2024-02-02", ..., "2024-02-29"]
 * @example mapDaysInMonth("2024-04") // ["2024-04-01", "2024-04-02", ..., "2024-04-30"]
 * @example mapDaysInMonth("invalid") // []
 */
export declare function mapDaysInMonth(month: string): string[];