/**
 * CLI Error Explanation
 * Function for rendering full error documentation
 */
/**
 * Render full error documentation for --explain command.
 *
 * Constraints:
 * - Lookup from ERROR_REGISTRY
 * - Renders cause, resolution, examples sections
 *
 * @param errorId - Error identifier (format: RILL-{category}{3-digit})
 * @returns Formatted documentation string, or null if errorId is invalid/unknown
 *
 * @example
 * explainError("RILL-R009")
 * // Returns: formatted documentation with cause, resolution, examples
 *
 * @example
 * explainError("invalid")
 * // Returns: null
 */
export declare function explainError(errorId: string): string | null;