Add LangChain & LlamaIndex adapters, runnable examples, and CI smoke tests

[HiveForensicsAI]

Motivation

• Make KnoLo adoption-frictionless by providing production-ready adapters for LangChain and LlamaIndex so developers can drop KnoLo in as a retriever with minimal friction.
• Provide minimal, runnable ecosystem examples and CI smoke tests to guarantee an end-to-end developer flow completes quickly and reliably.
• Keep adapters as thin wrappers around @knolo/core without introducing new LLM logic or speculative APIs.

Description

• Implemented @knolo/langchain with KnoLoRetriever that loads a pack via mountPack (or accepts a pack) and returns LangChain-style Document objects populated with score, source, namespace, and id metadata via query from @knolo/core.
• Implemented @knolo/llamaindex with KnoLoRetriever exposing retrieve(query) that returns NodeWithScore-like objects { node: { text, metadata }, score } using mountPack + query.
• Added unit tests for both adapters under packages/langchain/test and packages/llamaindex/test to validate returned structures and metadata population, and extended create-knolo-app tests to run a generated-project knolo build to assert indexing.
• Added runnable examples in examples/ (langchain-basic, llamaindex-basic, node-cli-rag, nextjs-rag-chat), updated the root README.md with quickstarts and adapter snippets, and wired a CI workflow (.github/workflows/ci.yml) to run npm ci, npm run build, and npm test on PRs and pushes.

Testing

• Ran full workspace validation: npm install, npm run build, and npm test, and all automated tests passed successfully.
• Verified adapter unit tests passed when running npm test for @knolo/langchain and @knolo/llamaindex and they return the expected document/node shapes and metadata.
• Executed the examples smoke flows: examples/langchain-basic (npm install && npm run start), examples/llamaindex-basic (npm install && npm run start), examples/node-cli-rag (npm install && npm run build-pack && npm run query), and examples/nextjs-rag-chat (npm install && npm run start), and each completed successfully in this environment.

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