Decision guide for four narrow, optional UI libraries that solve one specific problem outside `ts-shadcn-ui`'s core component system: React Bits (animated/ decorative polish), assistant-ui (AI chat interface primitives), driver.js (onboarding tours and feature spotlights), and Tailark (prebuilt marketing/ landing-page blocks via the shadcn registry). Each is opt-in per-project, not part of the standard build order — load this skill only when one of these four specific needs comes up. Does NOT replace ts-shadcn-ui for core app components, or ts-nextjs-app-router for routing/rendering architecture.
