Clean up MVP output handling

internal/framework/pipeline/runner.go

@@ -49,10 +49,6 @@ type RunOutput struct {
 	Rejected    []artifacts.RejectedArtifact `json:"rejected,omitempty"`
 	Warnings    []contracts.Warning          `json:"warnings,omitempty"`
 	OutputFiles []contracts.OutputFile       `json:"-"`
-	// EncodedOutput is the legacy single-output payload. New callers should use OutputFiles.
-	EncodedOutput []byte `json:"-"`
-	// ContentType is the legacy single-output content type. New callers should use OutputFiles.
-	ContentType string `json:"content_type,omitempty"`
 }
 
 func (r *Runner) Run(ctx context.Context, input RunInput) (RunOutput, error) {
@@ -143,10 +139,6 @@ func (r *Runner) Run(ctx context.Context, input RunInput) (RunOutput, error) {
 		return failOutput(output), fmt.Errorf("validate output files from encoder %q: %w", encoder.Key(), err)
 	}
 	output.OutputFiles = files
-	if len(encoded.Files) == 0 {
-		output.EncodedOutput = append([]byte(nil), encoded.Bytes...)
-		output.ContentType = encoded.ContentType
-	}
 
 	return output, nil
 }
@@ -425,19 +417,8 @@ func manifestMetadataKey(module any) string {
 }
 
 func outputFilesFromResult(result contracts.OutputResult) ([]contracts.OutputFile, error) {
-	files := result.Files
-	if len(files) == 0 && len(result.Bytes) > 0 {
-		files = []contracts.OutputFile{
-			{
-				Name:        "output",
-				ContentType: result.ContentType,
-				Bytes:       result.Bytes,
-			},
-		}
-	}
-
-	out := make([]contracts.OutputFile, 0, len(files))
-	for _, file := range files {
+	out := make([]contracts.OutputFile, 0, len(result.Files))
+	for _, file := range result.Files {
 		if err := validateOutputFileName(file.Name); err != nil {
 			return nil, err
 		}