Every React app accumulates toggleable UI — a confirmation dialog, a mobile nav drawer, a settings popover, a notification panel. The state behind each one is always the same: a boolean, a way to open, a way to close, and maybe a callback for analytics or focus management when the transition happens. So you write useState(false) and three inline handlers, copy-paste it to the next modal, and somewhere around the fifth disclosure widget you notice you've scattered the same five-line pattern acr...