/**
 * @file `readBazelVersionFile(workspaceDir)` — walks up from `workspaceDir`
 *   looking for a `.bazelversion` file (the Bazel/Bazelisk convention for
 *   pinning the project's Bazel version). Returns the trimmed contents as a
 *   version string, or `undefined` when no file is found before reaching the
 *   filesystem root. The walk respects the "first `.bazelversion` wins"
 *   convention used by Bazelisk itself. Some special values that
 *   `.bazelversion` can hold (`latest`, `last_green`, `rolling`, etc.) are
 *   returned verbatim; resolution of those into concrete X.Y.Z versions is the
 *   orchestrator's job.
 */
export declare function readBazelVersionFile(startDir: string): Promise<string | undefined>;
