/**
 * Prompts the user for input and validates it.
 *
 * @param prompt - Question to display
 * @param validate - Validator function. Return `null` if valid, or error message string if invalid.
 * @param defaultValue - Optional default value if user presses enter
 * @returns A validated string from user input
 */
export declare function askValidated(prompt: string, validate: (input: string) => string | null, defaultValue?: string): Promise<string>;