feat(rag): hybrid multi-path search with RRF fusion

Add configurable hybrid mode on KnowledgeSearchPort that fuses dense unfiltered, dense filtered, and lexical ranks via RRF while preserving dense-compatible threshold scores. Archives Delivery 2 OpenSpec change.
2026-07-27 18:33:31 +08:00
parent ac1f831903
commit 376ad0c241
19 changed files with 661 additions and 8 deletions
@@ -0,0 +1,5 @@
+# Evidence
+
+- Delivery 1 identity/port foundation required
+- RRF utility and hybrid adapter unit tests green
+- Lexical sparse-lite intentionally intermediate until BM25 schema