export declare const REACHABLE_TEST_IDS_ATTRIBUTE = "data-pygmalion-reachable-testids";
/** Test ids whose rendered controls can actually be reached from this frame. */
export declare function reachablePreviewTestIds(root: ParentNode): readonly string[];
/** Stamps capture-time reachability without mutating the running document. */
export declare function stampReachablePreviewTestIds(source: Document, clone: HTMLElement): void;
/** Reads a capture-time reachability index, or null for a legacy snapshot. */
export declare function indexedReachablePreviewTestIds(markup: string): readonly string[] | null;