/**
 * Formats a cluster member count for display inside `MapCluster`.
 *
 * Rules:
 * - `n < 1 000` → raw integer string
 * - `1 000 ≤ n < 1 000 000` → `Xk` (truncated to whole thousands)
 * - `n ≥ 1 000 000` → `X.Xm` (truncated to one decimal of millions)
 *
 * Truncation (not rounding) is used so the displayed value never overstates the count.
 */
export declare const formatClusterCount: (n: number) => string;