Returns the project's hostname registry: the hostnames observed serving this project, when each was first and last seen, the last observed origin, and whether it is blocked. limits gives the registry's observed-host limit and retention; truncated is true when the list was cut at that limit. propagationSeconds is how long a policy change takes to reach the edge.

If the hostname service is unavailable the response is 503, never an empty list.

Required scope: project:manage