Implement final fixes and close out the implemetation roadmap

internal/framework/pipeline/debug.go

@@ -471,7 +471,7 @@ func debugSourceDocumentEnvelope(doc *source.SourceDocument) *debugSourceDocumen
 		Kind:     doc.Kind,
 		Format:   doc.Format,
 		Digest:   doc.Digest,
-		Units:    cloneSourceUnits(doc.Units),
+		Units:    cloneSourceUnitsForDebug(doc.Units),
 		Metadata: redactSensitiveMap(doc.Metadata),
 	}
 }
@@ -483,13 +483,21 @@ func debugSourceChunkEnvelope(chunk source.Chunk) debugSourceChunk {
 		Index:           chunk.Index,
 		Ref:             chunk.Ref,
 		Content:         debugContentEnvelope(chunk.Content, chunk.MediaType, chunk.Metadata, nil),
-		Units:           cloneSourceUnits(chunk.Units),
+		Units:           cloneSourceUnitsForDebug(chunk.Units),
 		Metadata:        redactSensitiveMap(chunk.Metadata),
 		Annotations:     source.CloneChunkAnnotations(chunk.Annotations),
 		PlanAnnotations: source.CloneChunkAnnotations(chunk.PlanAnnotations),
 	}
 }
 
+func cloneSourceUnitsForDebug(units []source.SourceUnit) []source.SourceUnit {
+	cloned, err := cloneSourceUnits(units)
+	if err != nil {
+		return nil
+	}
+	return cloned
+}
+
 func debugSourceChunkEnvelopes(chunks []source.Chunk) []debugSourceChunk {
 	if len(chunks) == 0 {
 		return nil