Live built-image inventory for one channel, newest first.

The tenant-scoped sibling of the admin host-detail images payload (routes/admin_hosts.py::_host_images): one read-only RPC per page load — no caching, no retries — filtered on the agent by the channel's full-UUID labels. images degrades to null (never an error) when the host has no registered RemoteHostAgent or the agent is unreachable, so the console settings page always renders. build_queue is deliberately NOT exposed — it is host-global and would leak other tenants' activity (admin-only). Each image's charged_size_bytes and matched_base come from the build record in the control DB (:func:~xhostd.deploy.pipeline.charged_sizes), joined on the agent row's image_id; an image with no record carries null.