/**
 * ActionRouter 统一错误码。客户端可据此做 switch/case 程序化处理。
 * @phase2 Phase 2 预留 — 统一 Action 路由启用后消费。
 */
export declare const ErrorCodes: {
    readonly MISSING_ACTION: "MISSING_ACTION";
    readonly UNKNOWN_ACTION: "UNKNOWN_ACTION";
    readonly MISSING_REQUIRED_PARAM: "MISSING_REQUIRED_PARAM";
    readonly HANDLER_ERROR: "HANDLER_ERROR";
};
export type ErrorCode = typeof ErrorCodes[keyof typeof ErrorCodes];