import { getDbExec } from "../db/client.js";
export declare function userFirstTouchColumnValues(attribution: Record<string, string | undefined> | undefined): Array<[column: string, value: string]>;
/** First touch wins: a value already on the row is never overwritten. */
export declare function persistUserFirstTouchAttribution(userId: string, attribution: Record<string, string | undefined> | undefined, exec?: Pick<ReturnType<typeof getDbExec>, "execute">): Promise<boolean>;