/** Shared fetch defaults for HTML search fallbacks (reduce naive bot blocking). */
export declare const HTML_SEARCH_USER_AGENT = "Mozilla/5.0 (compatible; xopc/1.0; +https://github.com/xopcai/xopc)";
export declare const DEFAULT_HTML_SEARCH_TIMEOUT_MS = 25000;
export declare function mergeAbortWithTimeout(signal: AbortSignal | undefined, ms: number): AbortSignal;