Add run manifest and logical output file contracts

internal/framework/contracts/contracts_test.go

@@ -230,11 +230,44 @@ func TestFakeMergeNormalizeAndOutputContracts(t *testing.T) {
 	if encoder.Key() != "generic-output" {
 		t.Fatalf("OutputEncoder.Key() = %q, want generic-output", encoder.Key())
 	}
-	if encoded.ContentType != "application/json" {
-		t.Fatalf("ContentType = %q, want application/json", encoded.ContentType)
+	if len(encoded.Files) != 1 {
+		t.Fatalf("len(Files) = %d, want 1", len(encoded.Files))
 	}
-	if string(encoded.Bytes) != `{"run_id":"run-1","approved_count":1}` {
-		t.Fatalf("Bytes = %s, want encoded output", encoded.Bytes)
+	if encoded.Files[0].ContentType != "application/json" {
+		t.Fatalf("ContentType = %q, want application/json", encoded.Files[0].ContentType)
+	}
+	if string(encoded.Files[0].Bytes) != `{"run_id":"run-1","approved_count":1}` {
+		t.Fatalf("Bytes = %s, want encoded output", encoded.Files[0].Bytes)
+	}
+}
+
+func TestOutputFileJSONShapeOmitsBytes(t *testing.T) {
+	file := OutputFile{
+		Name:        "artifacts/events.json",
+		ContentType: "application/json",
+		Bytes:       []byte(`{"ignored":true}`),
+	}
+
+	encoded, err := json.Marshal(file)
+	if err != nil {
+		t.Fatalf("json.Marshal() error = %v, want nil", err)
+	}
+
+	var got map[string]any
+	if err := json.Unmarshal(encoded, &got); err != nil {
+		t.Fatalf("json.Unmarshal() error = %v, want nil", err)
+	}
+	if got["name"] != "artifacts/events.json" {
+		t.Fatalf("name = %#v, want logical file name", got["name"])
+	}
+	if got["content_type"] != "application/json" {
+		t.Fatalf("content_type = %#v, want application/json", got["content_type"])
+	}
+	if _, ok := got["Bytes"]; ok {
+		t.Fatalf("encoded output file leaked Bytes: %s", encoded)
+	}
+	if _, ok := got["bytes"]; ok {
+		t.Fatalf("encoded output file leaked bytes: %s", encoded)
 	}
 }
 
@@ -397,7 +430,12 @@ func (encoder fakeOutputEncoder) Key() string {
 
 func (encoder fakeOutputEncoder) Encode(ctx context.Context, req OutputRequest) (OutputResult, error) {
 	return OutputResult{
-		Bytes:       []byte(`{"run_id":"` + req.Manifest.RunID + `","approved_count":1}`),
-		ContentType: "application/json",
+		Files: []OutputFile{
+			{
+				Name:        "artifacts/generic.json",
+				ContentType: "application/json",
+				Bytes:       []byte(`{"run_id":"` + req.Manifest.RunID + `","approved_count":1}`),
+			},
+		},
 	}, nil
 }