Add captured configuration comparison

docs/roadmap/implementation.md

@@ -82,6 +82,12 @@ existing validation, and attribution matches the selected source revision.
 
 ## Stage 2: Add The Private Bridge And Public Method
 
+**Status: Complete.** Added the private captured-result bridge and public
+`ConfigurationInspection.Diff` method. External-package tests cover changed and
+equal values, operand direction, self-comparison, and all zero-view pairs.
+`GOTOOLCHAIN=local go test . ./internal/configuration ./internal/engine` and
+`git diff --check` passed.
+
 Scope: the small integration path and basic facade tests.
 
 1. In `internal/configuration/inspection.go`, add the private wrapper and