/** Error taxonomy: callers branch on `code`, never on message text. */
export type NightWatchErrorCode = 'CANONICALIZE_FAILED' | 'LEDGER_CORRUPT' | 'LEDGER_LOCKED' | 'STORE_NOT_FOUND' | 'GIT_UNAVAILABLE' | 'CHECKPOINT_FAILED' | 'INVALID_PAYLOAD' | 'SETTINGS_MERGE_FAILED' | 'SIGNING_FAILED' | 'VERIFY_FAILED';
export declare class NightWatchError extends Error {
    readonly code: NightWatchErrorCode;
    readonly detail: Readonly<Record<string, unknown>>;
    constructor(code: NightWatchErrorCode, message: string, detail?: Record<string, unknown>);
}
export declare function isNightWatchError(value: unknown): value is NightWatchError;
/** Normalize any thrown value into a printable one-line message. */
export declare function describeError(value: unknown): string;