- Skip CAA lookup entirely when NODE is an IP address; show
"not checked (IP address scan)" instead of spuriously querying
IP octets as domain labels and reporting "not offered"
- Force FQDN (trailing dot) on the initial caa_node before the
walk loop so dig does not apply the resolv.conf search domain
to the first query, which could return a false result
- Add a visible warning in the scan header when scanning by IP
address, noting that trust/CAA and other domain-specific checks
may be unreliable and the user should rescan with the hostname
