/** Edge build of the registry's filesystem leg (`#actions/host-files`):
 *  there is no disk on Web-standard runtimes, so every optional host config
 *  file reads as absent and the registry composes from inline config alone.
 *  Keep this module free of node builtins; the portability gate bundles it. */
export declare function readOptionalVendoJson<T>(_dir: string, _file: string, _parse: (value: unknown) => T): Promise<T | undefined>;