📝 docs: add comprehensive LangGraph development principles and project documentation

- Introduce CLAUDE.md with detailed development principles for LangGraph, including monorepo structure, shared dependencies, agent configuration, and deployment guidelines.
- Add README.md outlining the LangGraph-UP monorepo, key features, quick start instructions, architecture overview, and development commands.
- Enhance documentation for multi-provider model loading, agent orchestration patterns, and testing procedures.

Author: webup