/**
 * Reusable countdown timer for dialog components.
 * [WHO]: CountdownTimer
 * [FROM]: @catui/tui
 * [TO]: Consumed by modes/interactive/components/extension-input.ts, modes/interactive/components/extension-selector.ts
 * [HERE]: modes/interactive/components/countdown-timer.ts - owned by modes/interactive/AGENT.md
 */
import type { TUI } from "@catui/tui";
export declare class CountdownTimer {
    private tui;
    private onTick;
    private onExpire;
    private intervalId;
    private remainingSeconds;
    constructor(timeoutMs: number, tui: TUI | undefined, onTick: (seconds: number) => void, onExpire: () => void);
    dispose(): void;
}