/**
 * Request ID middleware — generates a UUID per request and attaches as header.
 */
import type { ServerResponse } from 'node:http';
/**
 * Generate a new request ID and set it on the response.
 */
export declare function assignRequestId(res: ServerResponse): string;
/**
 * Structured log line with request ID.
 */
export declare function logWithId(requestId: string, level: string, message: string): void;
