DNS lookup API: resolve any DNS record via Cloudflare's 1.1.1.1 DNS-over-HTTPS resolver with DNSSEC validation status. Types A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, SRV, PTR; returns the full answer section (name, type code, TTL, data). NXDOMAIN returns an unpaid 404. Use for infrastructure checks, email deliverability, domain verification, and security tooling by agents. Cached up to 5 minutes.