Execute ordered pipeline steps with barriers

internal/framework/pipeline/runner.go

@@ -59,6 +59,7 @@ type RunInput struct {
 
 	pipeline  ResolvedPipeline
 	llmClient contracts.StructuredLLMClient
+	stepID    string
 }
 
 type RunOutput struct {
@@ -249,12 +250,16 @@ func (r *Runner) Run(ctx context.Context, input RunInput) (output RunOutput, err
 	}
 
 	if chunkResult.accepted {
-		laneOutput, laneErr := r.runLanes(ctx, input, checkpoints, checkpointLoader, doc, sourceInput, sessionID, chunkResult.chunks)
-		if err := mergeLaneOutput(&output, laneOutput); err != nil {
-			return failOutput(output), err
-		}
-		if laneErr != nil {
-			return failOutput(output), laneErr
+		for _, step := range input.Prepared.Steps {
+			stepInput := input
+			stepInput.stepID = step.ID
+			laneOutput, laneErr := r.runLanes(ctx, stepInput, step, checkpoints, checkpointLoader, doc, sourceInput, sessionID, chunkResult.chunks)
+			if err := mergeLaneOutput(&output, laneOutput); err != nil {
+				return failOutput(output), err
+			}
+			if laneErr != nil {
+				return failOutput(output), fmt.Errorf("execute pipeline step %q: %w", step.ID, laneErr)
+			}
 		}
 	}
 
@@ -460,7 +465,10 @@ func validateRunInput(input RunInput) error {
 	if mode != ChunkCacheBypass && input.ChunkPlans == nil {
 		return fmt.Errorf("chunk plan store is required for %q mode", mode)
 	}
-	return validateResolvedPipeline(input.Prepared.resolved)
+	if err := validateResolvedPipeline(input.Prepared.resolved); err != nil {
+		return err
+	}
+	return rejectGeneratedBindings(input.Prepared.resolved)
 }
 
 func validateResolvedPipeline(pipeline ResolvedPipeline) error {