Desired and Observed State Should Never Share a Field
Operator intent and device-reported reality can disagree legitimately during rollout, reboot, outage or rollback.
fleet
Status Heartbeats Need Identity, Version and Health Context
A backend cannot manage a fleet from a last-seen timestamp alone.
Device Enrollment and Heartbeat Are Different Events
Enrollment establishes trusted identity; heartbeat reports what an already known device is doing.
Firmware Acceptance Should End in an Observable ACTIVE State
A successful download is not the same thing as a successful deployment.