feat: Implement Authentik group synchronization and add confirmation dialogs for service management

OTSSignsOrchestrator.Desktop/Views/ConfirmationDialog.axaml.cs

@@ -0,0 +1,50 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+
+namespace OTSSignsOrchestrator.Desktop.Views;
+
+/// <summary>
+/// A simple Yes/No confirmation dialog that can be shown modally.
+/// Use <see cref="ShowAsync"/> for a convenient one-liner.
+/// </summary>
+public partial class ConfirmationDialog : Window
+{
+    public bool Result { get; private set; }
+
+    public ConfirmationDialog()
+    {
+        InitializeComponent();
+    }
+
+    public ConfirmationDialog(string title, string message) : this()
+    {
+        TitleText.Text   = title;
+        MessageText.Text = message;
+        Title            = title;
+
+        ConfirmButton.Click += OnConfirmClicked;
+        CancelButton.Click  += OnCancelClicked;
+    }
+
+    private void OnConfirmClicked(object? sender, RoutedEventArgs e)
+    {
+        Result = true;
+        Close();
+    }
+
+    private void OnCancelClicked(object? sender, RoutedEventArgs e)
+    {
+        Result = false;
+        Close();
+    }
+
+    /// <summary>
+    /// Shows a modal confirmation dialog and returns true if the user confirmed.
+    /// </summary>
+    public static async Task<bool> ShowAsync(Window owner, string title, string message)
+    {
+        var dialog = new ConfirmationDialog(title, message);
+        await dialog.ShowDialog(owner);
+        return dialog.Result;
+    }
+}