feat(mobile/telemetry): collect real network type via connectivity_plus

- Add connectivity_plus: ^6.0.3 to pubspec.yaml
- DeviceInfoCollector._getNetworkType() calls Connectivity().checkConnectivity()
  and maps ConnectivityResult → wifi / mobile / ethernet / vpn / bluetooth / none / unknown
- networkType field in DeviceContext is now populated on every cold start
- All page_view and session events carry the accurate network type in device props

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/genex-mobile/lib/core/telemetry/collectors/device_info_collector.dart

@@ -1,6 +1,7 @@
 import 'dart:io';
 import 'package:device_info_plus/device_info_plus.dart';
 import 'package:package_info_plus/package_info_plus.dart';
+import 'package:connectivity_plus/connectivity_plus.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart';
 import '../models/device_context.dart';
@@ -25,6 +26,7 @@ class DeviceInfoCollector {
     final deviceInfo = DeviceInfoPlugin();
     final packageInfo = await PackageInfo.fromPlatform();
     final mediaQuery = MediaQuery.of(context);
+    final networkType = await _getNetworkType();
 
     DeviceContext result;
 
@@ -49,7 +51,7 @@ class DeviceInfoCollector {
         locale: Platform.localeName,
         timezone: DateTime.now().timeZoneName,
         isDarkMode: mediaQuery.platformBrightness == Brightness.dark,
-        networkType: 'unknown', // 需要额外的connectivity包
+        networkType: networkType,
         collectedAt: DateTime.now(),
       );
     } else if (Platform.isIOS) {
@@ -73,7 +75,7 @@ class DeviceInfoCollector {
         locale: Platform.localeName,
         timezone: DateTime.now().timeZoneName,
         isDarkMode: mediaQuery.platformBrightness == Brightness.dark,
-        networkType: 'unknown',
+        networkType: networkType,
         collectedAt: DateTime.now(),
       );
     } else {
@@ -84,6 +86,40 @@ class DeviceInfoCollector {
     return result;
   }
 
+  /// 获取当前网络类型
+  ///
+  /// 返回值：'wifi' | 'mobile_2g' | 'mobile_3g' | 'mobile_4g' | 'mobile_5g' |
+  ///         'ethernet' | 'vpn' | 'bluetooth' | 'none' | 'unknown'
+  Future<String> _getNetworkType() async {
+    try {
+      final results = await Connectivity().checkConnectivity();
+      // checkConnectivity 返回 List<ConnectivityResult>，取第一个主要连接
+      final result = results.isNotEmpty ? results.first : ConnectivityResult.none;
+      return _mapConnectivityResult(result);
+    } catch (e) {
+      return 'unknown';
+    }
+  }
+
+  String _mapConnectivityResult(ConnectivityResult result) {
+    switch (result) {
+      case ConnectivityResult.wifi:
+        return 'wifi';
+      case ConnectivityResult.mobile:
+        return 'mobile'; // 无法区分 2G/3G/4G/5G（需原生插件）
+      case ConnectivityResult.ethernet:
+        return 'ethernet';
+      case ConnectivityResult.vpn:
+        return 'vpn';
+      case ConnectivityResult.bluetooth:
+        return 'bluetooth';
+      case ConnectivityResult.none:
+        return 'none';
+      default:
+        return 'unknown';
+    }
+  }
+
   /// 收集屏幕信息
   ScreenInfo _collectScreenInfo(MediaQueryData mediaQuery) {
     final size = mediaQuery.size;

frontend/genex-mobile/pubspec.yaml

@@ -35,6 +35,7 @@ dependencies:
   sign_in_with_apple: ^6.1.0
   flutter_riverpod: ^2.5.1
   fpdart: ^1.1.0
+  connectivity_plus: ^6.0.3
 
 dev_dependencies:
   flutter_test: