Run now set last_run_at to the click, and a schedule's next turn counts
from last_run_at, so a manual run of the nightly prune at 14:00 moved
every later run to 14:00. Operator ruling: "run now shouldn't change the
schedule it should just run the playbook and leave the schedule as it
was."
Run now no longer touches last_run_at. It still records the run as
last_run_id, so the list shows it and a firing during it is skipped.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
