Class-name composition for Shadix components.
cn/1 flattens a list of class values and joins the truthy, non-empty ones
with single spaces. It does NOT resolve conflicting Tailwind utilities — that
is handled by Tailwind v4 cascade layers, so a caller's class always wins over
a component default regardless of order.
Summary
Functions
Joins a (possibly nested) list of class values into a single class string,
dropping nil, false, and empty strings.