/**
 * The lease name for one twin's feed.
 *
 * ── Domain and instance are required; the source is not ───────────────────
 * A feed is registered per instance, so domain plus instance already names it
 * uniquely. The source is appended when known because it is what a person
 * reading `task_leases` wants to see — which system this channel talks to.
 *
 * Missing a domain or an instance is refused rather than filled in. A blank
 * there would collapse two different feeds onto one name, and the failure
 * would be that one of them silently stops: it would look exactly like
 * "someone else holds it", which is the ordinary case on every instance but
 * one, so nothing would be logged.
 */
export declare function liveFeedLeaseName(domainId: string, instanceId: string, source?: string): string;