Each effect on a rule is a row with its settings at a glance, a button
to open it and one to drop it; an Add effect button unfolds the rest.
A fresh install seeds only the deliveroo rule. Preview updated.
Rules watch every notification for words and apps and answer with an
effect: nudge, flash, banner, airplane, confetti, blink, sound, focus,
or a command. Silenced notifications that match a rule are let through.
Settings popup behind a bar bell, rules kept in one JSON file.