/**
 * Pipeline step: download — file download with concurrency and progress.
 *
 * Supports:
 * - Direct HTTP downloads (images, documents)
 * - yt-dlp integration for video platforms
 * - Browser cookie forwarding for authenticated downloads
 * - Filename templating and deduplication
 */
import type { IPage } from '../../types.js';
export interface DownloadResult {
    status: 'success' | 'skipped' | 'failed';
    path?: string;
    size?: number;
    error?: string;
    duration?: number;
}
export declare function stepDownload(page: IPage | null, params: unknown, data: unknown, args: Record<string, unknown>): Promise<unknown>;