/**
 * Unknown Direct component resilience (`ssr-unknown-component-error-node`).
 * Leaf failure → subtree error node; do not throw out of document SSR.
 */
import type { SerializeTreeNode } from './dom-core.types.js';
export declare const UNKNOWN_COMPONENT_ERROR = "unknown-component";
/** Append a leaf diagnostic for tooling (does not replace the error node). */
export declare function noteUnknownComponent(name: string, via?: string): void;
/** SSR serialize-tree error node (keeps document HTTP 200). */
export declare function serializeUnknownComponentNode(name: string): SerializeTreeNode;
/** Live DOM error host (client create / schedule). */
export declare function createUnknownComponentElement(name: string, via?: string): HTMLElement;
/** Mark an existing island host as unknown (resume / EventEntry). */
export declare function markUnknownComponentHost(el: HTMLElement, name: string, via?: string): void;