feat:"初始化仓库，并更新基础代码。"

lib/main.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'providers/expense_provider.dart';
+import 'screens/home_screen.dart';
+
+void main() {
+  runApp(const MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MultiProvider(
+      providers: [
+        ChangeNotifierProvider(create: (_) => ExpenseProvider()..loadData()),
+      ],
+      child: MaterialApp(
+        title: 'Expense Tracker',
+        theme: ThemeData(
+          colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+          useMaterial3: true,
+        ),
+        home: const HomeScreen(),
+      ),
+    );
+  }
+}