import type { UnderstandingSourceItem } from './types.js';
export interface ActivityTopic {
    canonicalKey: string;
    title: string;
    summary: string;
    horizon: 'current' | 'ongoing' | 'long_term';
    confidence: number;
    evidenceRefs: string[];
    sourceIds: string[];
}
export declare function clusterActivityTopics(items: UnderstandingSourceItem[], now?: number): ActivityTopic[];