/**
 * Velocity anomaly detection — pure statistical functions.
 *
 * Given time-bucketed commit counts, detects periods where the count
 * deviates significantly from the mean (spikes / drops).
 */
export interface VelocityBucket {
    period: string;
    count: number;
}
export interface VelocityAnomaly {
    period: string;
    count: number;
    mean: number;
    stddev: number;
    direction: "spike" | "drop";
    /** Deviation magnitude in units of standard deviation (σ). */
    magnitude: number;
}
export interface VelocityAnomalyResult {
    mean: number;
    stddev: number;
    thresholdSigma: number;
    totalBuckets: number;
    anomalies: VelocityAnomaly[];
}
/**
 * Detect anomalous periods in a time series of commit counts.
 *
 * A period is anomalous when `|count - mean| > thresholdSigma * stddev`.
 * When stddev is 0 (all values identical), no anomalies are returned.
 */
export declare function detectVelocityAnomalies(buckets: VelocityBucket[], thresholdSigma?: number): VelocityAnomalyResult;