/**
 * Class 1 drift classification over a stack's last CloudFormation operation
 * (drift-remediation plan § Phase 5 item 1). Fetches the failure events of
 * the most recent operation via `DescribeStackEvents` (newest-first), maps
 * them onto the shared NotFound anchors (`@fjall/util/aws` `driftSuspects`,
 * derived from the Phase 0 BC fixture `__tests__/fixtures/bc-stack-events.json`)
 * and returns out-of-band-deletion SUSPECTS — never verdicts; `driftProbe.ts`
 * confirms.
 *
 * Suspect `statusReason`s are masked at construction (a CloudFormation status
 * reason can embed anything a failed handler echoed), so journal writes and
 * CLI sinks may surface them directly.
 */
import { type Result } from "@fjall/generator";
import { type ResourceEvent } from "@fjall/util/aws";
import type { AwsProvider } from "../../aws/AwsProvider.js";
import type { DriftSuspect } from "../../types/drift.js";
/**
 * Fetch the events of the stack's most recent operation, newest-first. Pages
 * `DescribeStackEvents` until the operation's opening event (inclusive — the
 * shared `isOperationOpeningEvent` boundary, which a CancelUpdateStack
 * rollback's "User Initiated" stamp does NOT satisfy) or the page budget is
 * exhausted.
 */
export declare function fetchLastOperationEvents(aws: AwsProvider, stackName: string, abortSignal?: AbortSignal): Promise<Result<ResourceEvent[], Error>>;
/**
 * Classify a stack's last-operation events into drift suspects. Pure —
 * callers fetch events via {@link fetchLastOperationEvents} or hand over a
 * monitor's history.
 */
export declare function classifyDriftFailure(stackName: string, events: readonly ResourceEvent[]): DriftSuspect[];