/**
 * Lazy single-shot loader for the Vega runtime. `vega-embed` bundles `vega` +
 * `vega-lite` and a default tooltip handler; the dynamic `import()` keeps that
 * ~350 KB (gzipped) out of any downstream bundle that never renders a chart —
 * the reason `@molcrafts/molplot` is a separate package.
 *
 * `__setVegaEmbedForTesting` injects a stub so unit tests can assert on the
 * spec that would have been embedded without loading the real runtime.
 */
import type { EmbedOptions, Result, VisualizationSpec } from "vega-embed";
export type VegaEmbed = (el: HTMLElement, spec: VisualizationSpec, opts?: EmbedOptions) => Promise<Result>;
export declare function loadVegaEmbed(): Promise<VegaEmbed>;
/** Test-only hook. Pass a fake embed fn to inject; pass null to reset. */
export declare function __setVegaEmbedForTesting(embed: VegaEmbed | null): void;