fix：参考金值，研听，研值工程通用通用工程公共能力，重点对比网络请求、登录认证、状态管理、本地存储、WebView、推送、版本更新、一键登录、主题/UI 等模块，确定后续统一整改方案

lib/common/services/device_header_service.dart

@@ -5,13 +5,14 @@ import 'package:android_oaid/android_oaid.dart';
 import 'package:device_info_plus/device_info_plus.dart';
 import 'package:flutter/foundation.dart' show defaultTargetPlatform, kIsWeb;
 import 'package:flutter_paid/flutter_paid.dart';
-import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import 'package:package_info_plus/package_info_plus.dart';
 import 'package:platform_metadata/platform_metadata.dart';
 import 'package:uuid/uuid.dart';
 
 import '../storage/storage_keys.dart';
 import '../storage/storage_service.dart';
+import '../storage/preferences_storage.dart';
+import '../storage/secure_identity_storage.dart';
 import '../privacy/privacy_gate.dart';
 
 /// 请求公共 + 平台身份 header 来源（完全对齐研值契约）。
@@ -26,8 +27,6 @@ import '../privacy/privacy_gate.dart';
 class DeviceHeaderService {
   DeviceHeaderService._();
   static final DeviceHeaderService to = DeviceHeaderService._();
-  static const _storage = FlutterSecureStorage();
-  static const _kDeviceIdKey = 'device_id';
   // static const _platformMetadataChannel = MethodChannel('platform_metadata');
 
   // 渠道：优先编译期 --dart-define=UMENG_CHANNEL=xxx；Android 其次读 manifest，
@@ -48,6 +47,9 @@ class DeviceHeaderService {
   Future<void>? _baseInitialization;
   Future<void>? _identityInitialization;
 
+  SecureIdentityStorage get _identityStorage =>
+      SecureIdentityStorage(PreferencesStorage(StorageService.to.preferences));
+
   Future<void> ensureInitialized() async {
     _baseInitialization ??= _initializeBase();
     await _baseInitialization;
@@ -89,14 +91,14 @@ class DeviceHeaderService {
   /// X-Device-Id：iOS 优先 IDFV（per-vendor 稳定），否则 UUIDv4；
   /// 首次生成后写入 secure_storage，后续复用。
   Future<String> _resolveDeviceId() async {
-    final stored = await _storage.read(key: _kDeviceIdKey);
+    final stored = await _identityStorage.readDeviceId();
     if (stored != null && stored.isNotEmpty) return stored;
     var id = '';
     if (!kIsWeb && Platform.isIOS) {
       id = await _resolveIdfv();
     }
     if (id.isEmpty) id = const Uuid().v4();
-    await _storage.write(key: _kDeviceIdKey, value: id);
+    await _identityStorage.saveDeviceId(id);
     return id;
   }