A start in the past fires the latest missed time once, right away, so the
form says that instead of 'already passed'. A one-shot past its time reads
'past' / 'time passed' (the controller's clock, not a record of firing) and
keeps its pause button. The edit form compares against what it opened with,
so a schedule changing under it is not reverted on save.
/schedules lists the controller's scheduled prompts as cards: name as the
title, the agents it fires for, the message, its cadence and next fire.
Edit turns a card into its own form; pause, resume and remove act in place,
and + schedule opens an empty form. The form sends only what changed, so a
rename never moves the fire times, and warns when the start or the repeat
does. Filters reuse the shared card filter bar.
Adds a TextAreaField to the ui kit, and an upcoming mode on RelativeTime so
a next-fire time reads "in 5m". Needs the controller's /api/schedules
routes.
