Finish the references implementation for the extraction module and update roadmap documentation

internal/framework/pipeline/profile.go

@@ -135,6 +135,9 @@ func ResolvePipeline(profile PipelineProfile, options ResolveOptions, catalog Mo
 	if len(selectedLaneIDs) == 0 {
 		return ResolvedPipeline{}, fmt.Errorf("pipeline %q must select at least one artifact lane", pipelineID)
 	}
+	if err := validatePipelineReferenceDefaults(pipelineID, profile.References, lanesByID, catalog); err != nil {
+		return ResolvedPipeline{}, err
+	}
 
 	resolved := ResolvedPipeline{
 		ID:     pipelineID,
@@ -238,6 +241,44 @@ func resolveArtifactLane(
 	return lane, capabilities, nil
 }
 
+func validatePipelineReferenceDefaults(
+	pipelineID string,
+	pipelineReferences map[string]string,
+	lanesByID map[string]ArtifactLaneProfile,
+	catalog ModuleCatalog,
+) error {
+	normalizedPipelineReferences, err := normalizedReferenceMap(pipelineReferences, fmt.Sprintf("pipeline %q reference slot", pipelineID))
+	if err != nil {
+		return err
+	}
+	if len(normalizedPipelineReferences) == 0 {
+		return nil
+	}
+
+	declaredByAnyLane := make(map[string]struct{}, len(normalizedPipelineReferences))
+	for _, laneID := range sortedArtifactLaneProfileKeys(lanesByID) {
+		laneProfile := lanesByID[laneID]
+		extract := resolveBinding(laneProfile.Extract, "")
+		if extract.Module == "" {
+			return fmt.Errorf("pipeline %q lane %q extract module must not be empty", pipelineID, laneID)
+		}
+		extractSpec, err := extractorSpec(catalog, extract.Module)
+		if err != nil {
+			return moduleLookupError(pipelineID, laneID, StageExtract, extract.Module, err)
+		}
+		for _, slot := range extractSpec.ReferenceSlots {
+			declaredByAnyLane[slot.Name] = struct{}{}
+		}
+	}
+
+	for _, slotName := range sortedStringMapKeys(normalizedPipelineReferences) {
+		if _, ok := declaredByAnyLane[slotName]; !ok {
+			return fmt.Errorf("pipeline %q reference slot %q is not declared by any artifact lane", pipelineID, slotName)
+		}
+	}
+	return nil
+}
+
 func resolveReferenceBindings(
 	pipelineID string,
 	laneID string,
@@ -370,6 +411,18 @@ func normalizedReferenceMap(values map[string]string, keyName string) (map[strin
 	return out, nil
 }
 
+func sortedArtifactLaneProfileKeys(values map[string]ArtifactLaneProfile) []string {
+	if len(values) == 0 {
+		return nil
+	}
+	keys := make([]string, 0, len(values))
+	for key := range values {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
 func sortedStringMapKeys(values map[string]string) []string {
 	if len(values) == 0 {
 		return nil