feat:更新记录UI布局

lib/models/layout.dart

@@ -0,0 +1,16 @@
+import 'package:flutter/material.dart';
+
+/// 导航栏
+class NavItem {
+  final String label;
+  final IconData icon;
+  final IconData activeIcon;
+  final Widget page;
+
+  const NavItem({
+    required this.label,
+    required this.icon,
+    required this.activeIcon,
+    required this.page,
+  });
+}