/**
 * Score History — append-only ledger (.memoire/app-quality/history.jsonl) so
 * design debt is tracked over time, not just at a point in time. One JSON
 * object per line; capped so it never grows unbounded.
 *
 * Comparability rule: a run is only comparable to prior runs with the SAME
 * policy hash and a full (non-scoped) scan — comparing scores produced under
 * different thresholds, or from partial scans, is noise dressed as signal.
 */
import type { AppQualityDiagnosis } from "./engine.js";
export interface HistoryEntry {
    at: string;
    sha?: string;
    branch?: string;
    scope: "full" | "scoped";
    policyHash?: string;
    score: number;
    categoryScores: Record<string, number>;
    severityCounts: {
        critical: number;
        high: number;
        medium: number;
        low: number;
    };
}
export interface RegressionCheck {
    comparable: boolean;
    reason?: string;
    previous?: HistoryEntry;
    delta?: number;
    regressed?: boolean;
}
export declare function historyPath(projectRoot: string): string;
export declare function entryFromDiagnosis(diagnosis: AppQualityDiagnosis): HistoryEntry;
/** Append a run to the ledger, stamping git SHA/branch when available. */
export declare function appendHistory(projectRoot: string, diagnosis: AppQualityDiagnosis): Promise<HistoryEntry>;
export declare function readHistory(projectRoot: string): Promise<HistoryEntry[]>;
/**
 * Compare the current run against the most recent COMPARABLE prior entry
 * (same policy hash, full scan). Returns comparable:false with a reason when
 * no honest comparison exists — callers must not fabricate a trend from
 * incomparable runs.
 */
export declare function checkRegression(current: HistoryEntry, history: HistoryEntry[], budget: number): RegressionCheck;
/** Render a compact trend line for terminal display (oldest → newest, comparable entries only). */
export declare function renderTrend(history: HistoryEntry[], policyHash: string | undefined, limit?: number): string[];