Verify ConfigKit integration and record release handoff

docs/policy/testing.md

@@ -77,6 +77,13 @@ Do not add tests merely because a function, branch, or line exists. Do not add a
 
 Test through the narrowest stable boundary that expresses the behavior clearly.
 
+For application configuration, ConfigKit owns exhaustive YAML grammar,
+source traversal, import/overlay composition, provenance, and inspection
+renderer tests. Scriptorium tests its selected definition, source discovery,
+CLI override presence, command prerequisites, runtime conversion, credential
+boundary, and representative execution/inspection workflows with the tagged
+library. Do not copy the upstream parser test matrix into this repository.
+
 This is often the package API, but it may instead be:
 
 - a smaller pure function when dense domain logic is most clearly isolated there;