Migrate acquisition fixtures to document-root controls

internal/engine/destination_import_lifecycle_test.go

@@ -28,7 +28,7 @@ func TestRelativeImportsFeedFinalInheritanceAndInspectionLifecycle(t *testing.T)
 	load := func(dynamic string) *testResult[configuration] {
 		t.Helper()
 		directory := t.TempDir()
-		mainPath := writeImportFile(t, directory, "entry.yml", `configkit:
+		mainPath := writeImportFile(t, directory, "entry.yml", `config:
   imports:
     - path: parent.yml
       destination: [entries]
@@ -166,7 +166,7 @@ func TestRelativeImportMatchesWrappedPlacementAndSafeDiff(t *testing.T) {
 		options := LayeredOptions[map[string]any]{}
 		if relativeImport {
 			directory := t.TempDir()
-			mainPath := writeImportFile(t, directory, "main.yml", `configkit:
+			mainPath := writeImportFile(t, directory, "main.yml", `config:
   imports:
     - path: fragment.yml
       destination: [application]