Restructures project with feature-based organization

Refactors project structure to support modular, feature-driven development

Introduces comprehensive language localization support
Adds menu management with role-based access control
Implements dynamic sidebar and theme switching capabilities

Enhances project scalability and maintainability

app/Features/Menu/SideMenuViewComponent.cs

@@ -0,0 +1,35 @@
+using Microsoft.AspNetCore.Mvc;
+using CalendarServer.Features.Menu.Models;
+using CalendarServer.Features.Menu.Services;
+
+namespace CalendarServer.Features.Menu;
+
+/// <summary>
+/// ViewComponent for rendering the side menu based on user role.
+/// </summary>
+public class SideMenuViewComponent : ViewComponent
+{
+    private readonly IMenuService _menuService;
+
+    public SideMenuViewComponent(IMenuService menuService)
+    {
+        _menuService = menuService;
+    }
+
+    public IViewComponentResult Invoke(UserRole? role = null)
+    {
+        // Default to Admin for demo (in real app, get from auth)
+        var userRole = role ?? UserRole.Admin;
+
+        var currentUrl = HttpContext.Request.Path.Value;
+        var groups = _menuService.GetMenuForRole(userRole, currentUrl);
+
+        var viewModel = new SideMenuViewModel
+        {
+            Groups = groups,
+            CurrentUserRole = userRole
+        };
+
+        return View(viewModel);
+    }
+}