/**
 * Reads a File as a data URL while honoring an AbortSignal.
 *
 * @param file - Browser File selected by the user.
 * @param signal - Signal aborted by stale work or editor destruction.
 * @returns File contents represented as a data URL.
 */
export declare function readFileAsDataUrl(file: File, signal: AbortSignal): Promise<string>;
/**
 * Reads files concurrently as data URLs.
 *
 * @param files - Budget-validated files.
 * @param signal - Signal shared by the collection request.
 * @returns Data URLs in source file order.
 */
export declare function readFilesAsDataUrls(files: readonly File[], signal: AbortSignal): Promise<readonly string[]>;