/**
 * Resolve a filename relative to a directory. No containment is
 * enforced here: upward traversal and absolute filenames are allowed,
 * matching open() in other languages. The policy layer is the
 * allow-list (`assertContained`, layered on by callers that take
 * `allowedPaths`) and the approval interrupts raised by the stdlib
 * wrappers (`interrupt std::read` / `std::write` / `std::edit`).
 *
 * An absolute `filename` wins over `dir` (path.resolve semantics).
 * `~` expands in both arguments.
 */
export declare function resolvePath(dir: string, filename: string): Promise<string>;