Clean up MVP output handling

internal/framework/pipeline/registry_integration_test.go

@@ -193,7 +193,11 @@ func (output integrationOutput) Key() string {
 }
 
 func (output integrationOutput) Encode(ctx context.Context, req contracts.OutputRequest) (contracts.OutputResult, error) {
-	return contracts.OutputResult{Bytes: []byte(`{}`), ContentType: "application/json"}, nil
+	return contracts.OutputResult{
+		Files: []contracts.OutputFile{
+			{Name: "output.json", ContentType: "application/json", Bytes: []byte(`{}`)},
+		},
+	}, nil
 }
 
 type integrationValidator struct {

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
 		}

internal/framework/pipeline/runner_test.go

@@ -29,13 +29,11 @@ func TestNewAndDataTypes(t *testing.T) {
 		Metadata:  map[string]any{"request": "test"},
 	}
 	output := RunOutput{
-		Manifest:      artifacts.RunManifest{PipelineID: "pipeline-1"},
-		Approved:      []artifacts.Artifact{{ExtractorKey: "extract-alpha"}},
-		Rejected:      []artifacts.RejectedArtifact{{ValidatorName: "validator"}},
-		Warnings:      []contracts.Warning{{ReasonCode: "note", Message: "message"}},
-		OutputFiles:   []contracts.OutputFile{{Name: "artifacts/generic.json", ContentType: "application/json", Bytes: []byte(`{}`)}},
-		EncodedOutput: []byte(`{}`),
-		ContentType:   "application/json",
+		Manifest:    artifacts.RunManifest{PipelineID: "pipeline-1"},
+		Approved:    []artifacts.Artifact{{ExtractorKey: "extract-alpha"}},
+		Rejected:    []artifacts.RejectedArtifact{{ValidatorName: "validator"}},
+		Warnings:    []contracts.Warning{{ReasonCode: "note", Message: "message"}},
+		OutputFiles: []contracts.OutputFile{{Name: "artifacts/generic.json", ContentType: "application/json", Bytes: []byte(`{}`)}},
 	}
 
 	if input.Pipeline.ID != "pipeline-1" || input.SourceID != "source-1" {
@@ -1140,13 +1138,11 @@ func (validator *runnerValidator) Validate(ctx context.Context, req contracts.Va
 }
 
 type runnerOutputEncoder struct {
-	key         string
-	files       []contracts.OutputFile
-	bytes       []byte
-	contentType string
-	warnings    []contracts.Warning
-	err         error
-	requests    []contracts.OutputRequest
+	key      string
+	files    []contracts.OutputFile
+	warnings []contracts.Warning
+	err      error
+	requests []contracts.OutputRequest
 }
 
 func (encoder *runnerOutputEncoder) Key() string {
@@ -1156,10 +1152,8 @@ func (encoder *runnerOutputEncoder) Key() string {
 func (encoder *runnerOutputEncoder) Encode(ctx context.Context, req contracts.OutputRequest) (contracts.OutputResult, error) {
 	encoder.requests = append(encoder.requests, req)
 	return contracts.OutputResult{
-		Files:       encoder.files,
-		Bytes:       encoder.bytes,
-		ContentType: encoder.contentType,
-		Warnings:    encoder.warnings,
+		Files:    encoder.files,
+		Warnings: encoder.warnings,
 	}, encoder.err
 }
 

internal/framework/pipeline/walking_skeleton_test.go

@@ -36,10 +36,13 @@ func TestWalkingSkeletonFixture(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Run() error = %v, want nil", err)
 	}
-	if output.ContentType != "application/json" {
-		t.Fatalf("ContentType = %q, want application/json", output.ContentType)
+	if len(output.OutputFiles) != 1 {
+		t.Fatalf("len(OutputFiles) = %d, want 1", len(output.OutputFiles))
 	}
-	assertStructuralJSONEqual(t, output.EncodedOutput, expectedBytes)
+	if output.OutputFiles[0].ContentType != "application/json" {
+		t.Fatalf("ContentType = %q, want application/json", output.OutputFiles[0].ContentType)
+	}
+	assertStructuralJSONEqual(t, output.OutputFiles[0].Bytes, expectedBytes)
 	if llmClient.calls != 2 {
 		t.Fatalf("LLM calls = %d, want chunk count 2", llmClient.calls)
 	}
@@ -356,8 +359,9 @@ func (output walkingSkeletonOutput) Encode(ctx context.Context, req contracts.Ou
 		return contracts.OutputResult{}, err
 	}
 	return contracts.OutputResult{
-		Bytes:       encoded,
-		ContentType: "application/json",
+		Files: []contracts.OutputFile{
+			{Name: "output.json", ContentType: "application/json", Bytes: encoded},
+		},
 	}, nil
 }