feat(blackbox): the cab panel as fits the vehicle, every switch the driver worked in the events

- The rest of the cab record is read when written: what drives the
  vehicle, the doors' permits and departure signal, the brakes of the
  whole train, a diesel's oil and temperatures, the cruise control and
  the rest.
- Cab panel: the traction as fits what drives the vehicle (voltage and
  current of an electric one; revolutions, oil pressure and temperatures
  of a diesel; clutch or torque converter of a mechanical or hydraulic
  one; nothing for a draisine), the equalizing reservoir, the main
  reservoir pipe and the most braked cylinder of the train, the brakes'
  setting and mode, a group of the doors, the pumps of a diesel where an
  electric vehicle has its pantographs, the hand brake, the releaser, the
  horn's tone, the radio's channel, the integrated handle of a unit.
- Events: every switch on and off, doors opened and closed, the departure
  signal, the hand brake, the brakes' setting, the radio channel, the
  cruise control's speed; moving with the doors open and an overheating
  engine as faults.
- A vehicle with no lamps at an end (a draisine) is not judged on its
  lights, and one which never had a voltage shows none.

Eu07.BlackBox/HeadCodes.cs

@@ -71,7 +71,7 @@ public static class HeadCodes
     };
 
     /// <summary>Whether the head of the train showed what it was to; null when nothing tells it.</summary>
-    public static bool? HeadRight(CabSample sample) => sample.Movement switch
+    public static bool? HeadRight(CabSample sample) => NoLamps(sample.EquippedHead) ? null : sample.Movement switch
     {
         Movement.Train => Meets(sample.LightsHead, sample.EquippedHead, sample.LightHintHead, HeadCode.Pc1),
         Movement.Shunting => Shows(HeadCode.Tb1, sample.LightsHead, sample.EquippedHead),
@@ -79,7 +79,7 @@ public static class HeadCodes
     };
 
     /// <summary>Whether the tail of the train showed what it was to; null when nothing tells it.</summary>
-    public static bool? TailRight(CabSample sample) => sample.Movement switch
+    public static bool? TailRight(CabSample sample) => NoLamps(sample.EquippedTail) ? null : sample.Movement switch
     {
         Movement.Train => Meets(sample.LightsTail, sample.EquippedTail, sample.LightHintTail, HeadCode.Pc5),
         Movement.Shunting => Shows(HeadCode.Tb1, sample.LightsTail, sample.EquippedTail),
@@ -87,6 +87,12 @@ public static class HeadCodes
     };
 
     /// <summary>Whether both ends showed what they were to; null when nothing tells it.</summary>
+    /// <summary>
+    /// An end with no lamp at all, a draisine's: the simulator still asks it for a signal it can't show, so it
+    /// is not judged. A recording made before the lamps were written can't tell.
+    /// </summary>
+    public static bool NoLamps(Lights? equipped) => equipped == Lights.None;
+
     public static bool? Right(CabSample sample) =>
         HeadRight(sample) is { } head && TailRight(sample) is { } tail ? head && tail : null;