/**
 * Read a domain-specific knowledge hint.
 * Returns the first non-empty line from the file, trimmed to 20 tokens (≈120 chars).
 * Returns undefined if no file exists for this domain.
 */
export declare function readKnowledgeHint(hostname: string): Promise<string | undefined>;
/**
 * Append a discovery note to the domain knowledge file.
 * Called automatically by healing.ts after recovering a lost element (Rule 16).
 */
export declare function appendKnowledgeHint(hostname: string, note: string): Promise<void>;