# Acceptance: rag-hybrid-search-rrf

## Result

Hybrid mode implemented on KnowledgeSearchPort:

- dense unfiltered + dense filtered + lexical rank over union
- RRF fusion by evidenceKey
- dense-compatible score preserved for thresholds
- default mode remains dense

## Verification

```text
mvn -q "-Dtest=RrfFusionTest,VectorKnowledgeSearchAdapterHybridTest,LookupKnowledgeToolTest" test
```

Pass.

## Residual

- True Milvus BM25/sparse schema + reindex still follow-up
- Lexical path only ranks dense-recalled candidates (does not expand pure-term misses outside dense topK)