v2.25.7

Fixed

• DNS records no longer reported "missing" when the lookup failed (#555). A
  Passive Scan Deep FP review surfaced false HIGH findings — "No A/AAAA record",
  "No NS records", "SPF record missing", "DMARC record missing" — on live domains
  (stripe.com, gitlab.com) that demonstrably have all of them. Root cause:
  _resolve/_get_txt_record returned [] for both "record absent" and a
  failed lookup (timeout/SERVFAIL/NoNameservers/resolver rate-limiting), so an
  empty result read as "missing". They now return a _DnsResult carrying
  .resolved (plus one retry); the missing-record checks (A/AAAA, NS, MX, CAA,
  SPF, DMARC) gate on it, so a failed lookup is treated as "unknown", never
  "missing". _DnsResult subclasses list, so existing callers/mocks are
  unchanged.