# Evidence: rag-eval-hybrid-baseline

## Pre-change

- `generate_rag_lookup_snapshots.ps1` passed `-Dretrieval.vector-store.mode=spring`.
- Fixtures had `caseId/query/retrievedAt/lookupResult` only.
- Offline eval already supported Hit levels, recall@K, baseline diff.

## User decisions

- Scope: knife-1 only (no dual fixture dirs).
- Acceptance: wiring required; fixture refresh best-effort (env allowed full refresh).

## Apply-discovered

- After hybrid refresh, `chat-l0-filter-fallback` failed: pure rank→quality made topSimilarity=1.0 on decoy-only filtered hits → no unfiltered retry.
- Fix: optional `denseDistance` on hybrid hits; quality gate uses L2 when present; sort order remains RRF.