Add knowledge-rag — Production RAG with hybrid search + cross-encoder reranking

[lyonzin]

knowledge-rag

GitHub: https://github.com/lyonzin/knowledge-rag
PyPI: pip install knowledge-rag
Author: Lyon.

A production-ready local RAG system implementing several advanced techniques from this repo:

• Hybrid Search: Semantic (FastEmbed ONNX) + BM25 keyword with Reciprocal Rank Fusion
• Cross-Encoder Reranking: ms-marco-MiniLM-L-6-v2 post-retrieval
• Context-Aware Chunking: Markdown-aware splitting by section headers
• Query Expansion: Dictionary-based synonym expansion for technical terms
• Evaluation: Built-in MRR@5 and Recall@5 metrics via MCP tool

Designed as an MCP server for Claude Code with 12 tools including CRUD operations, URL ingestion, similarity search, and retrieval evaluation. Zero external dependencies.