Adds **rag-kb** — a local-first, completely free agent memory & knowledge service.
- Hybrid retrieval for Chinese & English: BGE-M3 dense vectors + BM25 (jieba), fused with RRF
- Local-first & offline-capable: single process, embedded ChromaDB, no external services; retrieval works with the network cut off
- Dual protocol: REST + native MCP server from the same process
- Fully functional without any LLM; optional Ollama/cloud unlocks RAG answering
- Apache-2.0, English README included
Submitted by the project author. Happy to adjust the entry if needed.
