feat(core): 设备号改用系统标识，重装不再变成新游客

- Android 读 SSAID、iOS 读 IDFV，均免权限，由原生通道提供，不引插件
- 取不到时回退本地 UUIDv4，替代原来 32 位随机 + 时间戳的拼接

ios/Runner/AppDelegate.swift

@@ -63,6 +63,7 @@ final class RunnerFlutterViewController: FlutterViewController {
   func didInitializeImplicitFlutterEngine(_ engineBridge: FlutterImplicitEngineBridge) {
     GeneratedPluginRegistrant.register(with: engineBridge.pluginRegistry)
     registerWirelessDataChannel(engineBridge)
+    registerDeviceIdChannel(engineBridge)
     let channel = FlutterMethodChannel(
       name: "com.stormg.lumadrama/share",
       binaryMessenger: engineBridge.applicationRegistrar.messenger()
@@ -144,6 +145,21 @@ final class RunnerFlutterViewController: FlutterViewController {
     }
   }
 
+  /// 设备标识：IDFV 免权限，卸载本 App 不变，避免客户端自生成的 id 每次重装都变。
+  private func registerDeviceIdChannel(_ engineBridge: FlutterImplicitEngineBridge) {
+    let channel = FlutterMethodChannel(
+      name: "com.stormg.lumadrama/device",
+      binaryMessenger: engineBridge.applicationRegistrar.messenger()
+    )
+    channel.setMethodCallHandler { call, result in
+      guard call.method == "idfv" else {
+        result(FlutterMethodNotImplemented)
+        return
+      }
+      result(UIDevice.current.identifierForVendor?.uuidString)
+    }
+  }
+
   private func registerWirelessDataChannel(_ engineBridge: FlutterImplicitEngineBridge) {
     let channel = FlutterMethodChannel(
       name: WirelessDataPrompt.channelName,