Adds Online group to application menu and localization

Introduces new menu group with Booking and Website sections
Updates Danish localization to include new menu items and group

Enhances application navigation with online-related features

PlanTempus.Application/Features/Localization/Translations/da.json

@@ -8,6 +8,8 @@
     "customers": "Kunder",
     "employees": "Medarbejdere",
     "services": "Services",
+    "booking": "Booking",
+    "website": "Website",
     "reports": "Statistik & Rapporter",
     "settings": "Indstillinger",
     "account": "Abonnement & Konto"
@@ -15,6 +17,7 @@
   "groups": {
     "overview": "Overblik",
     "data": "Data",
+    "online": "Online",
     "analytics": "Analyse",
     "system": "System"
   },

PlanTempus.Application/Features/Menu/Services/MockMenuService.cs

@@ -143,12 +143,41 @@ public class MockMenuService : IMenuService
                 }
             },
 
+            // ONLINE GROUP
+            new MenuGroup
+            {
+                Id = "online",
+                Label = "Online",
+                SortOrder = 3,
+                Items = new List<MenuItem>
+                {
+                    new MenuItem
+                    {
+                        Id = "booking",
+                        Label = "Booking",
+                        Icon = "ph-calendar-check",
+                        Url = "/online-booking",
+                        MinimumRole = UserRole.Manager,
+                        SortOrder = 1
+                    },
+                    new MenuItem
+                    {
+                        Id = "website",
+                        Label = "Website",
+                        Icon = "ph-globe",
+                        Url = "/website",
+                        MinimumRole = UserRole.Manager,
+                        SortOrder = 2
+                    }
+                }
+            },
+
             // ANALYSE GROUP
             new MenuGroup
             {
                 Id = "analytics",
                 Label = "Analyse",
-                SortOrder = 3,
+                SortOrder = 4,
                 Items = new List<MenuItem>
                 {
                     new MenuItem
@@ -168,7 +197,7 @@ public class MockMenuService : IMenuService
             {
                 Id = "system",
                 Label = "System",
-                SortOrder = 4,
+                SortOrder = 5,
                 Items = new List<MenuItem>
                 {
                     new MenuItem