damocles's #472 returns `{ ok, failed, missing, one_shot_consumed }`
from the fire-now endpoint. Parse the response and flash the
per-target outcome on the button itself for ~1.5s before
refreshSchedules() repaints — operator sees the result
immediately without a modal alert or an `/api/schedules`
re-fetch round-trip.
Button label transitions:
↯ fire now → ◐ firing… → ↯ fired: 3 ok, 1 missing — consumed
(green flash, then row refresh)
f35382e57c