Preserve explicit code candidates and expose verified model asset milestones

docs/MIXED-QUALITY.md

@@ -105,8 +105,10 @@ restart or substituted model was used. Reproduce with the
 
 ## Open quality gates
 
-- Correct the documented All-files audio-intent suppression without hiding
-  legitimate media results; validate candidate preservation before ranking.
+- Validate the subsequent explicit-code routing fix on broader mixed queries
+  without hiding legitimate media results. A tiny real-model candidate-preservation
+  regression passed; see [routing evidence](RETRIEVAL-ROUTING.md). The frozen
+  baseline recorded here remains the pre-fix measurement.
 - Evaluate general/code query task fusion on a new independently labelled set,
   with bounded retrieval and measured cache/filter costs.
 - Improve music discrimination and precise speech timestamps.