/**
 * In-memory event bus for the local UI.
 *
 * Tiny synchronous fan-out: publishers (route adapters, orchestrator hook,
 * update observer) call `publish`; SSE connections subscribe and receive every
 * event until they unsubscribe. Listener errors are caught so one broken
 * client cannot break others.
 */
import type { LocalUiEvent } from './types.js';
export type LocalUiEventListener = (event: LocalUiEvent) => void;
export declare class EventBus {
    private readonly listeners;
    publish(event: LocalUiEvent): void;
    subscribe(listener: LocalUiEventListener): () => void;
    /** Test helper. */
    listenerCount(): number;
}