/**
 * The one-shot handshake between the supervisor (which performs an update) and
 * the freshly-spawned server (which announces the outcome to the board group).
 * Written by the supervisor after `/update`, read+deleted once on server boot.
 */
export interface UpdateResult {
    ok: boolean;
    version?: string;
    error?: string;
}
export declare function writeUpdateResult(r: UpdateResult): void;
/** Read the pending update result, deleting it so it announces exactly once. */
export declare function readAndClearUpdateResult(): UpdateResult | null;