The restart decision was a shell variable set by comparing the fetched
value with the file just before overwriting it. A run that wrote the
file and then failed before the restart (the matrix unit's registration
render, or `systemctl --machine` finding no bus yet) left a retry that
saw an unchanged file and never restarted the consumer.
The file is now written only when the value differs, so its mtime marks
the last real change, and `refresh_consumer <machine> <unit> <path>`
compares that mtime with the consumer's ActiveEnterTimestamp on every
run, the shape the openbao client-CA refresh in swarm-bao.nix already
uses. A consumer that started after the last change is left alone; a
running one is try-restarted, a failed one reset and started, all with
--no-block, and nothing happens while the container is down.
The helper's comment block also exceeded the 30-line limit
(`comment-block lint` failed on d871467d); its per-function notes now
sit beside the functions.
module-eval-bao-grants asserts the gated write, the path the refresh is
keyed on, and the mtime-vs-start comparison for each consumer.
Refs #4662
b68fd7306e