/**
 * Vega-Lite lazy loading (spec: "Available globals in widget script blocks").
 * Vega + Vega-Lite + vega-embed (~500KB) are not bundled — injected from a
 * CDN on first actual use and cached thereafter. `vegaEmbedProxy` is the
 * stable function reference handed to every widget script's closure; only
 * *calling* it triggers the load, so passing it around before first use is free.
 */
declare global {
    interface Window {
        vegaEmbed?: (el: Element, spec: unknown, opts?: unknown) => Promise<{
            view: {
                finalize(): void;
            };
        }>;
    }
}
export declare function ensureVegaLoaded(): Promise<void>;
export declare function vegaEmbedProxy(el: Element, spec: unknown, opts?: unknown): Promise<{
    view: {
        finalize(): void;
    };
}>;