app working with sandbox

lib/screens/main_shell.dart

@@ -1,14 +1,13 @@
-/// Host scaffold that owns the bottom navigation bar and its four tabs.
+/// Host scaffold that owns the bottom navigation bar and its tabs.
 library;
 
 import 'package:flutter/material.dart';
 
-import 'home_screen.dart';
-import 'profile_screen.dart';
-import 'search_screen.dart';
+import 'balance_screen.dart';
 import 'settings_screen.dart';
+import 'transactions_screen.dart';
 
-/// Switches between Home, Search, Profile, and Settings without stacking routes.
+/// Switches between Balance, Transactions, and Settings without stacking routes.
 class MainShell extends StatefulWidget {
   const MainShell({super.key});
 
@@ -20,9 +19,8 @@ class _MainShellState extends State<MainShell> {
   int _index = 0;
 
   static const _pages = [
-    HomeScreen(),
-    SearchScreen(),
-    ProfileScreen(),
+    BalanceScreen(),
+    TransactionsScreen(),
     SettingsScreen(),
   ];
 
@@ -38,19 +36,14 @@ class _MainShellState extends State<MainShell> {
         onDestinationSelected: (index) => setState(() => _index = index),
         destinations: const [
           NavigationDestination(
-            icon: Icon(Icons.home_outlined),
-            selectedIcon: Icon(Icons.home),
-            label: 'Home',
+            icon: Icon(Icons.account_balance_wallet_outlined),
+            selectedIcon: Icon(Icons.account_balance_wallet),
+            label: 'Balance',
           ),
           NavigationDestination(
-            icon: Icon(Icons.search_outlined),
-            selectedIcon: Icon(Icons.search),
-            label: 'Search',
-          ),
-          NavigationDestination(
-            icon: Icon(Icons.person_outline),
-            selectedIcon: Icon(Icons.person),
-            label: 'Profile',
+            icon: Icon(Icons.receipt_long_outlined),
+            selectedIcon: Icon(Icons.receipt_long),
+            label: 'Transactions',
           ),
           NavigationDestination(
             icon: Icon(Icons.settings_outlined),