/**
 * Shared Route53-delegation heuristic — the ONE implementation behind both
 * the CLI's `fjall domain verify` and the webapp's manage_domain verify
 * operation, so the two surfaces can never disagree on the same zone.
 *
 * DNS is case-insensitive (RFC 4343) and dns0x20 query randomisation
 * legitimately returns upper/mixed-case NS names, so matching MUST be
 * case-insensitive; zone-file-shaped inputs carry a trailing dot, so that is
 * shed too. Both are handled by routing through `normaliseRecordName`.
 *
 * The `awsdns` substring test is deliberately a HEURISTIC, not hardening: it
 * matches any name containing `awsdns` (Route53's name-server namespace,
 * `ns-*.awsdns-NN.{com,net,org,co.uk}`). Delegation verification is a
 * user-facing readiness signal, not a security boundary.
 */
/** True when a single NS name looks like a Route53 name server. */
export declare function isRoute53NameServer(ns: string): boolean;
/**
 * True when ANY of the zone's name servers is a Route53 name server — the
 * delegation verdict for a resolver's NS answer. Empty input is `false`
 * (no answer proves nothing).
 */
export declare function isDelegatedToRoute53(nameservers: readonly string[]): boolean;