fix: 恢复首页Tab

- 还原提交 f69f05c 中删除的首页导航项
- 恢复5个Tab: 首页、行情、交易、资产、我的
- 修复因缺少首页导致的应用问题

flutter_monisuo/lib/ui/pages/main/main_page.dart

@@ -32,6 +32,7 @@ class _MainPageState extends State<MainPage> {
   final Set<int> _loadedPages = {0};
 
   static final _navItems = [
+    _NavItem(label: '首页', icon: LucideIcons.house, page: const HomePage()),
     _NavItem(label: '行情', icon: LucideIcons.trendingUp, page: const MarketPage()),
     _NavItem(label: '交易', icon: LucideIcons.arrowLeftRight, page: const TradePage()),
     _NavItem(label: '资产', icon: LucideIcons.wallet, page: const AssetPage()),