The status field was being decorated with "(last seen ...)" suffix
which broke frontend statusVariant() matching and prevented the
LastSeen column from showing the separate timestamp.
Changes:
- machineToResp() now returns clean status ("online"/"offline")
- MachineResponse includes last_seen_at and created_at as separate fields
- Fix whitespace typo in WakeCheckIntervalSeconds field
darroyo
bf9bcccde2