import type { Board } from "./model.js";
export interface AlternativeChange {
    entity: "board" | "job" | "track" | "artifact" | "region";
    id: string;
    field: string;
    before: unknown;
    after: unknown;
}
export interface AlternativeConflict extends AlternativeChange {
    current: unknown;
}
export interface AlternativePreview {
    sourceBoard: string;
    alternativeBoard: string;
    baselineId: string;
    /** Exact canonical review token, not a cryptographic signature or authorization. */
    basis: string;
    changes: AlternativeChange[];
    conflicts: AlternativeConflict[];
    problems: string[];
    canAccept: boolean;
}
/** The caller must load the immutable baseline from storage, never from a client payload. */
export declare function previewAlternative(source: Board, alternative: Board, baseline: Board): AlternativePreview;
/** Call inside the source write lock and reload both designs before checking the review token. */
export declare function acceptAlternative(source: Board, alternative: Board, baseline: Board, expectedBasis: string): Board;