使用 assets_util 来管理 assets

lib/screens/main_screen.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import '../widgets/floating_icon.dart';
+import '../utils/assets_util.dart';
 
 class MainScreen extends StatefulWidget {
   const MainScreen({super.key});
@@ -26,9 +27,9 @@ class _MainScreenState extends State<MainScreen> {
       body: Stack(
         children: [
           Container(
-            decoration: const BoxDecoration(
+            decoration: BoxDecoration(
               image: DecorationImage(
-                image: AssetImage('assets/images/bg.jpg', package: 'ai_chat_assistant'),
+                image: AssetsUtil.getImage('bg.jpg'),
                 fit: BoxFit.cover,
               ),
             ),