Inside-out view composition: foldkit-mixins

foldkit-mixins gives Foldkit views typed extension points.

A component author decides which structural points may be customized — root, input, label, trigger, and so on. The caller can later attach appearance and element-level behavior to those points without copying the component's markup or asking the component author to add another prop.

That is what "inside-out" means here: customization is authored outside the component, but it attaches to extension points deliberately published from inside the component.