Expose input destinations through the public facade

records.go

@@ -182,12 +182,16 @@ type Location struct {
 // SourceInfo describes a source discovered during a load. Kind identifies its
 // acquisition, independent of Layer. Path is canonical for a host file and
 // namespace-relative for a filesystem file; synthetic sources have no Path.
+// Destination is the effective mapping path where this source contributes.
 // UnderlayIndex is the one-based original underlay position, or zero for other
 // sources. ImportedFrom identifies the declaration that included this source.
 type SourceInfo struct {
-	ID            string
-	Label         string
-	Path          string
+	ID    string
+	Label string
+	Path  string
+	// Destination is the effective mapping path. Imported sources retain their
+	// input's destination; overlay and CLI sources use the root path.
+	Destination   Path
 	Layer         Layer
 	Kind          SourceKind
 	UnderlayIndex int
@@ -260,6 +264,7 @@ func cloneLocations(locations []Location) []Location {
 }
 
 func cloneSourceInfo(source SourceInfo) SourceInfo {
+	source.Destination = source.Destination.clone()
 	source.ImportedFrom = cloneLocation(source.ImportedFrom)
 	return source
 }