Add lumen-langchain-kit to Web3 libraries

[Lumen-Founder]

Hello! I'd like to contribute a useful Web3 library for dapp developers.

lumen-langchain-kit is an NPM package that provides LangChain integration for LUMEN World Computer on Base Mainnet. It enables AI agents to interact with decentralized context bus and autonomous agent kernel.

This library will be helpful for developers building AI-powered decentralized applications.

Thank you!

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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