fix(app): the share dialog shows the whole invitation, not only its subject

The text box was given its text before it was told to take several lines,
and a one-line box keeps only the first line of what it is given. Found by
the UI test for this dialog on its first run.

Refs #163

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>
Signed-off-by: James Maes <james@kof22.com>

gclo/MainWindow.xaml.cs

@@ -1204,13 +1204,15 @@ public sealed partial class MainWindow : Window
    /// <summary>The invitation as text to paste, for when no email program opened it.</summary>
    private ContentDialog NewShareDialog(ShareInvitation invitation)
    {
+      // AcceptsReturn before Text: a box that takes one line keeps only the first
+      // line of what it is given, which here would be the subject and nothing else.
       var text = new TextBox
       {
-         Text = invitation.AsPlainText,
-         IsReadOnly = true,
          AcceptsReturn = true,
          TextWrapping = TextWrapping.Wrap,
+         IsReadOnly = true,
          MaxHeight = 320,
+         Text = invitation.AsPlainText,
       };
       Microsoft.UI.Xaml.Automation.AutomationProperties.SetAutomationId(text, "ShareInvitationText");
       Microsoft.UI.Xaml.Automation.AutomationProperties.SetName(text, "Invitation text");