/**
 * `src/services/observability/aggregation-helpers.ts`
 *
 * The event-detail readers the aggregations in `aggregation.ts` are built on
 * (category test, `detail` field extraction, timestamp difference) and the
 * two event-source helpers the CLI calls. Moved verbatim (wave 3, file-size
 * cap campaign) so the aggregation module stays under the 300 raw-line cap.
 * The first four were module-private before the move and are NOT re-exported
 * from `aggregation.ts`; the two event-source helpers were public and are
 * re-exported there, so that module's public surface is unchanged.
 *
 * The per-slice repair-cycle count that used to live here moved to
 * `repair-cycle-metric.ts`: the version-1 counter this file carried counted
 * QA's own state transitions, not repair loops, and the corrected metric
 * needs its own module to keep the version marker and the legacy count
 * together.
 */
import { type ObservabilityEvent } from './observability-service.js';
export declare function isSliceTransition(event: ObservabilityEvent): event is ObservabilityEvent & {
    sliceRid: string;
};
export declare function artifactRole(event: ObservabilityEvent): string;
export declare function transitionTo(event: ObservabilityEvent): string | null;
export declare function durationMsBetween(firstTs: string, lastTs: string): number;
export declare function readAllSessionEvents(projectRoot: string): ObservabilityEvent[];
export declare function readSessionEvents(projectRoot: string, sessionId: string): ObservabilityEvent[];