The versions page shows each node's update state with update buttons, API
tokens get a release scope that can only register releases (used by CI), and
the CI image and release builds now pass the tag, commit and build time.
Probes connect to the panel directly and get the agent list as desired state.
CI signs the image digest of agent and probe releases, the panel forwards the
manifest, and a host updater verifies it with a local public key, pulls by
digest and rolls back when the new version is unhealthy.