# ctrl/cluster.sh

## Why list and free live here

`list` and `free` live in `cluster.sh` rather than in a separate script because a
near-identical second name (cluster / clusters) is a trap — you reach for one and
get the other. One target, one file, unambiguous subcommands.

## Idempotent means convergent

"Idempotent" here means convergent, not "exits early if the cluster exists".
That distinction matters: an interrupted first run can leave a cluster created
but not finished, and returning early on the re-run would strand it there. The
create step is conditional; every step after it always runs, and each one is
individually idempotent.