CI signs the image digest of each agent and probe release; the panel only
stores and forwards it. Nodes write the manifest to their data directory and
a host updater verifies the signature with a local public key, pulls by
digest, restarts the unit and rolls back when it is unhealthy. The panel can
list releases, ask a node to update and show the reported update state.
Agents and probes report OS, arch and build (version, tag, commit, time).
The backend looks up country and ISP of public addresses only, stores them
in node_meta (schema v5) and exposes display info via /api/public/nodes,
/api/public/about and /api/admin/build-info behind site.show_build.
justme