update --check: updates, newRequired, removed.
The report is what keeps the server-side picture honest:
- The panel’s install counts and per-skill install lists reflect what devices last reported.
- The device’s last-seen time in the devices page updates on every sync.
update --check runs a sync as part of its work, so you rarely need sync on its own — it exists as the explicit, apply-nothing way to report in. There is no background daemon; the registry learns about a machine only when a command runs.