StepContent was a component defined inside Setup, so every state
change recreated it as a new component type, causing React to
unmount/remount it and snap focus back to autoFocus. Replaced with
inline conditional JSX blocks.
After first login, admins are redirected to a 4-step setup wizard:
1. Server hostname (FQDN)
2. Primary and secondary nameservers
3. Admin email and optional password change
4. Review and confirm
Setup state is persisted in the settings table (setup_complete=true).
Once complete, the redirect never triggers again. Settings are saved
to the DB and hostname is applied via hostnamectl.
NixReaper