fix(osi): 加固 Phase 0 验收实现（T-006）

contract/envelope.go

@@ -3,7 +3,6 @@ package contract
 type Envelope struct {
 	ServiceID  string `json:"serviceId"`
 	UploadInfo any    `json:"uploadinfo,omitempty"`
-	BaseInfo   any    `json:"baseInfo,omitempty"`
 }
 
 type UploadInfo struct {

contract/envelope_test.go

@@ -2,6 +2,7 @@ package contract
 
 import (
 	"encoding/json"
+	"reflect"
 	"testing"
 )
 
@@ -27,3 +28,9 @@ func TestEnvelopeUsesUploadInfoWithBaseAndManageInfo(t *testing.T) {
 		t.Fatalf("envelope JSON = %s", raw)
 	}
 }
+
+func TestEnvelopeDoesNotExposeTopLevelBaseInfo(t *testing.T) {
+	if _, ok := reflect.TypeOf(Envelope{}).FieldByName("BaseInfo"); ok {
+		t.Fatal("Envelope exposes obsolete top-level BaseInfo")
+	}
+}