feat: add Users and Settings nav items and routes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/admin/layout/Sidebar.jsx

@@ -1,11 +1,13 @@
 import { NavLink, useNavigate } from 'react-router-dom';
-import { LayoutDashboard, BarChart2, CheckSquare, Shield, LogOut } from 'lucide-react';
+import { LayoutDashboard, BarChart2, CheckSquare, Shield, LogOut, Users, Settings } from 'lucide-react';
 import { useAuth } from '../auth/useAuth';
 
 const NAV_ITEMS = [
   { to: '/admin/kanban', icon: LayoutDashboard, label: 'Канбан' },
   { to: '/admin/analytics', icon: BarChart2, label: 'Аналитика' },
   { to: '/admin/completed', icon: CheckSquare, label: 'Завершённые' },
+  { to: '/admin/users', icon: Users, label: 'Пользователи' },
+  { to: '/admin/settings', icon: Settings, label: 'Настройки' },
 ];
 
 const Sidebar = () => {