Web UI: zone naming and reverse zones, ACL suggestions, record form

- New zone dialog: choose Domain or Reverse zone. Reverse zones are
  created from a network and their name is generated; both kinds show the
  exact zone name and flag likely mistakes (addresses or URLs as names,
  host-like names, duplicates in the view, parent/child zones, networks
  off the octet/nibble boundaries) before anything is submitted.
- Record form: clears every field but the type after an add; shows the
  record exactly as it will be stored and warns about unqualified names.
  In reverse zones it takes an address, defaults to PTR, suggests host
  names of A/AAAA records with that address and warns about a second PTR;
  the record list shows addresses.
- Address match lists (options, view match lists, ACL elements) offer the
  existing ACLs, TSIG keys and built-ins as one-click suggestions and
  flag unknown names.
- Server: in reverse zones a record can be named by its address, and a
  PTR target like nas.example.com without the final dot is read as the
  full host name (a bare label is refused). Warnings noticed while parsing
  record data reach the result again.
- Fixes: brand link hover underline, the dashboard's "New zone" link
  opening the dialog twice.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/dnsname/dnsname.go

@@ -116,6 +116,12 @@ func Owner(input, zone string) (string, error) {
 	if in == "" || in == "@" {
 		return zone, nil
 	}
+	// In reverse zones an address stands for its PTR name.
+	if IsReverse(zone) {
+		if addr, err := netip.ParseAddr(strings.TrimSuffix(in, ".")); err == nil {
+			return ReverseName(addr), nil
+		}
+	}
 	a, err := ToASCII(in)
 	if err != nil {
 		return "", err