/**
 * Unified registration that handles both browser (customElements.define) and
 * SSR (internal registry) environments. Replace all bare customElements.define
 * calls with this so new components are automatically available to renderToStream.
 */
export declare function defineSSR(tagName: string, constructor: new () => HTMLElement): void;
export declare function getSSRConstructor(tagName: string): (new () => HTMLElement) | undefined;
export declare function getSSRRegistry(): ReadonlyMap<string, new () => HTMLElement>;