Deep-clone source metadata during chunk materialization

internal/framework/pipeline/runner.go

@@ -679,41 +679,11 @@ func validateOutputFileName(name string) error {
 }
 
 func cloneMetadata(metadata map[string]any) map[string]any {
-	if len(metadata) == 0 {
-		return nil
-	}
-	out := make(map[string]any, len(metadata))
-	for key, value := range metadata {
-		out[key] = cloneMetadataValue(value)
-	}
-	return out
-}
-
-func cloneMetadataValue(value any) any {
-	switch typed := value.(type) {
-	case map[string]any:
-		return cloneMetadata(typed)
-	case []any:
-		out := make([]any, len(typed))
-		for i := range typed {
-			out[i] = cloneMetadataValue(typed[i])
-		}
-		return out
-	case json.RawMessage:
-		return append(json.RawMessage(nil), typed...)
-	case []byte:
-		return append([]byte(nil), typed...)
-	case []string:
-		return append([]string(nil), typed...)
-	case map[string]string:
-		out := make(map[string]string, len(typed))
-		for key, item := range typed {
-			out[key] = item
-		}
-		return out
-	default:
-		return value
+	cloned, err := source.CloneMetadata(metadata)
+	if err != nil {
+		return metadata
 	}
+	return cloned
 }
 
 func cloneLLMProfiles(profiles []artifacts.LLMProfileManifest) []artifacts.LLMProfileManifest {