import { TaskStatus } from './task-state.js';
/**
 * Legal state transitions for the 10-state task FSM.
 *
 * Terminal states (COMPLETED, FAILED, CANCELLED, TIMED_OUT, UNKNOWN) are
 * absorbing — they have no outgoing transitions.
 *
 * UNKNOWN is reachable from every non-terminal state as a crash-recovery
 * fallback.
 *
 * Spec reference: §4.1
 */
export declare const VALID_TRANSITIONS: Record<TaskStatus, ReadonlySet<TaskStatus>>;
/**
 * Returns whether `from → to` is a legal FSM transition.
 */
export declare function isValidTransition(from: TaskStatus, to: TaskStatus): boolean;