Resolve merge conflict in style/pi-hole.css (keep both StaticDHCPTable
styles and DNSSEC query log styles).
Address outstanding reviewer feedback:
- Change save button icon from floppy-disk to checkmark to clarify it
confirms the row edit, not a final save
- Update hint text to mention "Save & Apply" is still needed
- Add hostname validation on the hostname cell (rejects spaces, commas,
and other characters invalid in DNS names)
Signed-off-by: Dominik <dl6er@dl6er.de>