Add React studio UI application shell

[eyshoit-commits]

Summary

• add a Vite-powered React/Tailwind workspace under apps/studio-ui with linting, testing, and build tooling for the Studio frontend
• implement the Studio layout, theming context, and JSON-RPC client wiring tabs for code editing, agent chat, execution, LLM playground, terminal streaming, and admin management
• deliver dedicated components for filesystem editing, sandbox execution, micro/wasm runners, LLM interactions, metrics-aware admin dashboards, and terminal streaming with reusable styling assets

Testing

• not run (npm packages unavailable in execution environment)

---

https://chatgpt.com/codex/tasks/task_e_68f41c4b21c08329a007a583504d7900