fix: 修复macos保存图片

lib/app/modules/hi_anti_lost/controllers/hi_anti_lost_controller.dart

@@ -1,6 +1,7 @@
 import 'dart:io';
 import 'dart:typed_data';
 import 'dart:ui' as ui;
+import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
@@ -15,35 +16,44 @@ class HIAntiLostController extends GetxController {
   Future<void> saveImage() async {
     // KRCommonUtil.kr_showLoading(message: "正在保存...");
     try {
-      // Check permission
-      final hasAccess = await Gal.hasAccess();
-      if (!hasAccess) {
-        await Gal.requestAccess();
-      }
-
       // Load image from assets
       final ByteData data =
           await rootBundle.load('assets/images/lost-share-image.png');
       final Uint8List pngBytes = data.buffer.asUint8List();
 
-      await Gal.putImageBytes(pngBytes);
+      if (Platform.isMacOS || Platform.isWindows || Platform.isLinux) {
+        // Desktop: Use FilePicker to save file
+        String? outputFile = await FilePicker.platform.saveFile(
+          dialogTitle: '保存图片',
+          fileName: 'Hi快联系方式',
+          type: FileType.custom,
+          allowedExtensions: ['png'],
+        );
 
-      String message = "已保存至系统相册";
-      if (Platform.isMacOS) {
-        message = "已保存至系统【照片】应用";
-      } else if (Platform.isWindows) {
-        message = "已保存至系统【图片】文件夹";
+        if (outputFile != null) {
+          final file = File(outputFile);
+          await file.writeAsBytes(pngBytes);
+          KRCommonUtil.kr_showToast("已保存至: $outputFile");
+        }
+      } else {
+        // Mobile: Use Gal to save to gallery
+        // Check permission
+        final hasAccess = await Gal.hasAccess();
+        if (!hasAccess) {
+          await Gal.requestAccess();
+        }
+
+        await Gal.putImageBytes(pngBytes);
+        HIDialog.show(
+          message: "已保存至系统相册",
+        );
       }
-
-      HIDialog.show(
-        message: message,
-      );
     } catch (e) {
       debugPrint("Save image error: $e");
       if (e is GalException) {
         KRCommonUtil.kr_showToast("保存失败: No Permission");
       } else {
-        KRCommonUtil.kr_showToast("保存失败");
+        KRCommonUtil.kr_showToast("保存失败: $e");
       }
     } finally {
       //KRCommonUtil.kr_hideLoading();