/**
 * SimulationState — live physics state exposed via chart.simulation getter.
 */
export interface SimulationSnapshot {
    readonly alpha: number;
    readonly settled: boolean;
    readonly tickCount: number;
    readonly bubbles: ReadonlyArray<{
        readonly id: string;
        readonly x: number;
        readonly y: number;
        readonly radius: number;
        readonly vx: number;
        readonly vy: number;
    }>;
}