[WIP] AdministrationWindow: Add HasContextLoaded property

Elwig/Windows/ContextWindow.cs

@@ -18,6 +18,8 @@ namespace Elwig.Windows {
             }
         }
 
+        protected bool HasContextLoaded { get; private set; }
+
         private bool _renewPending = false;
 
         private readonly RoutedCommand CtrlR = new("CtrlR", typeof(ContextWindow), [new KeyGesture(Key.R, ModifierKeys.Control)]);
@@ -52,6 +54,7 @@ namespace Elwig.Windows {
             using var ctx = new AppDbContext();
             await OnRenewContext(ctx);
             await OnInit(ctx);
+            HasContextLoaded = true;
             Mouse.OverrideCursor = null;
         }