The Held tab's model name opens a card: each replica with its node, state,
age, CPU and memory, the room for more found by dry-running the scheduler
on a copy of the inventory, and a form for the always-running and
under-load replica counts. An always-running count placement cannot meet
is refused with the reason. Headroom is also on the admin API.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>