import type { ActionClass, LedgerRecord } from '../core/record.js';
/**
 * Compress hundreds of tool events into a reviewable timeline. Consecutive
 * events sharing (action class, top-level area) merge into one phase — the
 * reviewer cares that the agent "edited src/utils for 40 minutes", not about
 * each of the 31 individual edits.
 */
export interface Phase {
    readonly startSeq: number;
    readonly endSeq: number;
    readonly startTs: string;
    readonly endTs: string;
    readonly cls: ActionClass;
    readonly area: string;
    readonly count: number;
    readonly sampleTargets: readonly string[];
}
export declare function buildTimeline(records: readonly LedgerRecord[]): readonly Phase[];
/** Top-level grouping key: first path segment for paths, class name otherwise. */
export declare function areaOf(target: string, cls: ActionClass): string;
export declare function spanHours(records: readonly LedgerRecord[]): number | undefined;