/**
 * Resolves an import path to an absolute path with leading slash.
 *
 * @param source The import source path (e.g., '/components/foo.mdx' or '../bar.mdx')
 * @param importingFilePath The path of the file containing the import
 * @returns The resolved absolute path with leading slash, or null if it's an external/package import
 */
export declare const resolveImportPath: (source: string, importingFilePath: string) => string | null;