Verify ownership across execution and repair

docs/roadmap/implementation.md

@@ -410,6 +410,17 @@ configured-default/runtime-override diagnostics through the public facade.
 
 ## Stage 15: Verify Cross-Path Ownership And Runtime Compatibility
 
+**Completed:** Cross-path checks cover mutations by an injected client on both
+initial and repair requests, detached results and details, concurrent details
+with claim/discard, and typed, numeric, null, cyclic, unsupported, and deep
+runtime provider values. Remaining validating copies serve configuration
+acceptance/overlay or public override acceptance; outward projections and schema
+detachment remain ownership boundaries. Go 1.27.3 `go test -race
+./internal/usecase ./internal/configuration ./internal/jsonvalue . -run
+'Prepared|Provider|Extra|Smoke|Profile|Schema'` passed (the filtered jsonvalue
+package selected no tests); the full `go test -race ./internal/jsonvalue` passed
+separately.
+
 **Findings:** 5–8. **Scope:** focused existing public and package contract tests.
 
 1. Reconcile the ownership inventory with the delivered call paths. Verify that