fix：app检测更新补充逻辑

lib/common/services/device_header_service.dart

@@ -34,6 +34,7 @@ class DeviceHeaderService {
   static const _umengChannel = String.fromEnvironment('UMENG_CHANNEL');
 
   String _deviceId = '';
+  String _packageName = '';
   String _version = '';
   String _build = '';
   String _deviceModel = '';
@@ -68,6 +69,7 @@ class DeviceHeaderService {
   Future<void> _initializeBase() async {
     try {
       final info = await PackageInfo.fromPlatform();
+      _packageName = info.packageName.trim();
       _version = info.version;
       _build = info.buildNumber;
     } catch (_) {}
@@ -244,6 +246,7 @@ class DeviceHeaderService {
   /// 公共 header（不含 token）。11
   Map<String, String> commonHeaders() => _compact({
     'X-Device-Id': _deviceId,
+    'pkg': _packageName,
     'User-Version': _version,
     'User-BuildID': _build,
     'User-Platform': _platform(),