/**
 * Sanitizes a filename by replacing spaces with underscores and removing invalid characters.
 * @param name - The filename to sanitize
 * @returns A sanitized filename string, truncated to 100 characters
 */
export declare function sanitizeFilename(name: string): string;
/**
 * Converts a string into a URL-friendly/filesystem-friendly slug.
 * Lowercases, replaces spaces with hyphens, removes non-alphanumeric except hyphens.
 */
export declare function slugify(text: string): string;
/**
 * Ensures the directory exists and saves content to a file.
 * @param filePath - The full path where the file should be saved.
 * @param content - The content to save (string or Buffer).
 * @param encoding - Optional encoding for writeFile (defaults based on content type).
 */
export declare function saveFile(filePath: string, content: string | Buffer, encoding?: BufferEncoding): Promise<void>;