Implement ordered pipeline step resolution

internal/cli/run.go

@@ -749,7 +749,7 @@ func effectiveLLMProfileIDs(resolved pipeline.ResolvedPipeline) []string {
 		}
 	}
 	add(resolved.Chunk)
-	for _, lane := range resolved.ArtifactLanes {
+	for _, lane := range resolved.AllArtifactLanes() {
 		add(lane.Extract)
 		add(lane.Merge)
 		add(lane.Normalize)
@@ -1178,17 +1178,34 @@ func selectedReferenceTargets(cfg config.Config, pipelineID string, only []strin
 	if !ok {
 		return nil, fmt.Errorf("pipeline %q is not configured", strings.TrimSpace(pipelineID))
 	}
+	if profile.Steps != nil && len(only) > 0 {
+		return nil, fmt.Errorf("pipeline %q --only is not supported for explicit ordered steps", strings.TrimSpace(pipelineID))
+	}
 
 	lanesByID := make(map[string]pipeline.ArtifactLaneProfile, len(profile.Artifacts))
-	for rawLaneID, lane := range profile.Artifacts {
-		laneID := strings.TrimSpace(rawLaneID)
-		if laneID == "" {
-			return nil, fmt.Errorf("pipeline %q artifact lane id must not be empty", strings.TrimSpace(pipelineID))
+	addLanes := func(values map[string]pipeline.ArtifactLaneProfile) error {
+		for rawLaneID, lane := range values {
+			laneID := strings.TrimSpace(rawLaneID)
+			if laneID == "" {
+				return fmt.Errorf("pipeline %q artifact lane id must not be empty", strings.TrimSpace(pipelineID))
+			}
+			if _, ok := lanesByID[laneID]; ok {
+				return fmt.Errorf("pipeline %q artifact lane %q is duplicated after trimming", strings.TrimSpace(pipelineID), laneID)
+			}
+			lanesByID[laneID] = lane
 		}
-		if _, ok := lanesByID[laneID]; ok {
-			return nil, fmt.Errorf("pipeline %q artifact lane %q is duplicated after trimming", strings.TrimSpace(pipelineID), laneID)
+		return nil
+	}
+	if profile.Steps == nil {
+		if err := addLanes(profile.Artifacts); err != nil {
+			return nil, err
+		}
+	} else {
+		for _, step := range profile.Steps {
+			if err := addLanes(step.Artifacts); err != nil {
+				return nil, err
+			}
 		}
-		lanesByID[laneID] = lane
 	}
 
 	selectedIDs := make([]string, 0, len(lanesByID))