- Add CSS custom properties for surfaces, text, borders, accent, radius, font stacks
- Add JetBrains Mono via next/font/google alongside Inter (both as CSS variables)
- Upgrade cn() from naive filter/join to twMerge(clsx()) for proper Tailwind class merging
- Standardize marketing section containers from max-w-7xl to max-w-6xl
- Install tailwind-merge and clsx dependencies
- LangChain: AgentLensCallbackHandler with auto-span creation for
LLM calls, tool calls, chains, and agent decision logging
- Dashboard: trace list with search, status filters, pagination
- Dashboard: trace detail with Decision/Span/Event tabs
- Dashboard: sidebar layout, responsive design, dark theme
