Mosaic UI

Two things live under Mosaic, and this skill covers the how-to for both:

• Styled components are authored with slot recipes — one recipe owns a part's slot identity (data-cl-slot), variants, state, and appearance cascade; useRecipe resolves it and hands back per-slot props to spread.
• Flows follow a machine → controller → view split that keeps Clerk resource logic out of visual components and makes behavior testable without a running Clerk app:

machine     Pure flow rules: states, events, guards, async invokes, errors.
            No React hooks. No Clerk hooks. No Clerk resource objects.

controller  Clerk/data adapter: reads Clerk hooks/resources, injects async
            effects into machine context, gates permissions, derives view props.
            The only layer that may import Clerk hooks or call resource methods.