import type { Express } from 'express';
/**
 * App-wide CORS helper (used by Explorer and optionally by API)
 *
 * - If an explicit origin string is provided (and not "*"), enable CORS for that
 *   exact origin and set credentials=true.
 * - If origin is omitted or "*", install a small wrapper that reflects the
 *   request's Origin header (permissive mode). This is convenient for
 *   development or single-tenant setups but should be scoped in production.
 */
export declare const cors: (app: Express, origin?: string) => void;