FindDOHEndpoint() for an arbitrary name parameter should fallback to query the _dns.<zone of name> ie closest SOA

[adam-burns]

If there is no _dns subdomain for the submitted name parameter, then _dns. (where zone is the closest name to the param with SOA record) should also be queried for an SVCB record.

if answer.Answer < 1, the Ns array already contains an array member that is the SOA record of the passed parameter

sig0namectl/golang/sig0/doh.go

Lines 62 to 65 in 33f6d1a

	if len(answer.Answer) < 1 {
	spew.Dump(answer)
	return nil, fmt.Errorf("findDOHEndpoint: no answer section for %s", lookup)
	}