feat: add calendar component with event management features including create, edit, delete, and share functionalities

src/components/Sidebar.jsx

@@ -1,5 +1,5 @@
 import { NavLink } from 'react-router-dom';
-import { LayoutDashboard, Settings, Shield, X, Palette, Globe } from 'lucide-react';
+import { LayoutDashboard, Settings, Shield, X, Palette, Globe, CalendarDays } from 'lucide-react';
 import BrandLogo from './BrandLogo';
 import { useAuth } from '../contexts/AuthContext';
 import { useLanguage } from '../contexts/LanguageContext';
@@ -30,6 +30,7 @@ export default function Sidebar({ open, onClose }) {
 
   const navItems = [
     { to: '/dashboard', icon: LayoutDashboard, label: t('nav.dashboard') },
+    { to: '/calendar', icon: CalendarDays, label: t('nav.calendar') },
     { to: '/federation/inbox', icon: Globe, label: t('nav.federation'), badge: federationCount },
     { to: '/settings', icon: Settings, label: t('nav.settings') },
   ];