Consolidate engine import defaults

internal/engine/layered.go

@@ -17,7 +17,7 @@ type Underlay struct{ Inputs []Input }
 // LayeredOptions selects lower-priority tiers and final application rules.
 type LayeredOptions[T any] struct {
 	Definition        Definition[T]
-	importDefaults    importDefaults
+	ImportDefaults    ImportDefaults
 	SourceVersionMode sourceVersionMode
 	Underlays         []Underlay
 	Overlay           string
@@ -41,7 +41,7 @@ func LoadLayered[T any](main Input, secrets SecretBinding, supplied ...LayeredOp
 			destination: main.Destination.clone(), placementMode: main.placementMode,
 		},
 		definition: options.Definition, sourceVersionMode: options.SourceVersionMode,
-		importDefaults:    snapshotImportDefaults(options.importDefaults),
+		importDefaults:    snapshotImportDefaults(options.ImportDefaults),
 		overlay:           options.Overlay,
 		overlayFilesystem: options.OverlayFilesystem,
 		overrides:         append([]Override(nil), options.Overrides...),