Expand module contracts for references and normalizer LLM access

internal/framework/pipeline/walking_skeleton_test.go

@@ -216,6 +216,10 @@ func (chunker walkingSkeletonChunker) Key() string {
 	return "fake/chunk"
 }
 
+func (chunker walkingSkeletonChunker) ReferenceSlots() []contracts.ReferenceSlot {
+	return nil
+}
+
 func (chunker walkingSkeletonChunker) Chunk(ctx context.Context, req contracts.ChunkRequest) (contracts.ChunkResult, error) {
 	if len(req.Source.Units) < 3 {
 		return contracts.ChunkResult{}, fmt.Errorf("fixture source must contain at least three units")
@@ -336,6 +340,10 @@ func (normalizer walkingSkeletonNormalizer) Key() string {
 	return DefaultNormalizeModule
 }
 
+func (normalizer walkingSkeletonNormalizer) ReferenceSlots() []contracts.ReferenceSlot {
+	return nil
+}
+
 func (normalizer walkingSkeletonNormalizer) Normalize(ctx context.Context, req contracts.NormalizeRequest) (contracts.NormalizeResult, error) {
 	return contracts.NormalizeResult{Candidates: req.Candidates}, nil
 }