Black box: the queries of the user's train worked out once a read, lights as the driver checks them

- The stations, the signals passed, the horn points, the couplings, the
  consists and the timetable progress of the user's train are kept until
  a read adds something; the views asked for them every frame, which on
  a long session with many trains took the window down. A read that adds
  nothing no longer counts as a change.
- The lights are checked against the lamps the vehicles at the ends have
  (written by the simulator from now on), as its driver checks them: Pc 1
  without the upper headlight, with the auxiliary lamps, Pc 5 with the
  rear-end signals. Only while the user drives: the autopilot's lights
  are its own.
- A train off the platform counts at both ends: its head past the stop
  point as well as its tail before the platform's end.
- A recording without the couplings keeps the timetable for any vehicle
  of the user.
- A signal passed at danger is ringed on the map only once it was.
- In the tapes window a black box opens on a click or Enter, not when
  the arrow keys go over it.
- The viewer's screenshot of a window not laid out saves nothing and
  still closes.

StarterNG/Views/Tapes/HaslerTapeWindow.cs

@@ -6,6 +6,7 @@ using System.Threading.Tasks;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
+using Avalonia.Input;
 using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Media.Imaging;
@@ -105,14 +106,19 @@ public sealed class HaslerTapeWindow : Window
         ToolTip.SetTip(_startClock, App.Loc["HaslerStartClockTip"]);
 
         ScrollViewer.SetHorizontalScrollBarVisibility(_list, ScrollBarVisibility.Disabled);
+        _list.KeyDown += async (_, e) =>
+        {
+            if (e.Key == Key.Enter && _list.SelectedItem is TreeViewItem { Tag: BlackBoxRecording box })
+            {
+                e.Handled = true;
+                await OpenBlackBoxAsync(box);
+            }
+        };
         _list.SelectionChanged += async (_, _) =>
         {
-            // A black box opens in a window of its own; the tape shown stays.
-            if (_list.SelectedItem is TreeViewItem { Tag: BlackBoxRecording box })
-            {
-                await OpenBlackBoxAsync(box);
+            // A black box opens in a window of its own on a click or Enter, not when the arrows go over it; the tape shown stays.
+            if (_list.SelectedItem is TreeViewItem { Tag: BlackBoxRecording })
                 return;
-            }
             // A session stands for its first tape, the player's own if it has one.
             if (_list.SelectedItem is TreeViewItem { Tag: TapeSession } session)
                 session.IsExpanded = true;