zhuyongxin
9cf162482d
refactor(rag): extract retrieval and ingest to py-rag service
- replace in-process Milvus stack with PyRagClient + PyRagKnowledgeSearchAdapter behind KnowledgeSearchPort (RERANK score passthrough)
- move document ingest to py-rag /documents:ingest; DocumentManagementService keeps MySQL ledger + local files
- sink L0 query understanding to py-rag; drop KnowledgeQueryTransformer, single UNFILTERED_VECTOR attempt
- remove Milvus deps, config classes, dead demo services and obsolete rebuild scripts
- compose/Makefile reduced to MySQL/Redis; add pyrag.* config