added two stroke scenario with vehicle

Program.cs

@@ -48,13 +48,17 @@ public class Program
     private static float _loadTarget = 0.0f;          // 0‑1
     private static float _loadCurrent = 0.0f;
 
+    private static float _clutchTarget = 0f;
+    private static float _clutchCurrent = 0f;
+    private static bool _cKeyHeld = false;
+
     private const int TargetMaxFill = (int)(SampleRate * 0.2);
 
     public static void Main()
     {
         var window = CreateWindow();
         LoadFont();
-        _scenario = new SingleCylScenario();
+        _scenario = new TwoStrokeScenario();
         _scenario.Font = _overlayFont;
         _scenario.Initialize(SampleRate);
         _lastThrottleUpdateTime = 0.0f;
@@ -102,6 +106,11 @@ public class Program
 
             _scenario.Throttle = _throttleCurrent;
 
+            float clutchDesired = _cKeyHeld ? 1f : 0f;
+            float clutchSmoothing = 1f - MathF.Exp(-ThrottleLerpRate * dtThrottle);
+            _clutchCurrent += (clutchDesired - _clutchCurrent) * clutchSmoothing;
+            _scenario.Clutch = _clutchCurrent;
+
 
             // ---- Drawing ----
             if (now - lastDrawTime >= 1.0 / DrawFrequency)
@@ -111,6 +120,7 @@ public class Program
                     string toggleHint = _isRealTime ? "[Space] slow mo" : "[Space] real time";
                     _overlayText.DisplayedString =
                         $"{toggleHint}  Speed: {_currentDisplaySpeed:F3}x  RT: {(_currentDisplaySpeed * 100.0):F1}%  Sim load: {_loadTracker.LoadPercent:F0}%\n" +
+                        $"Clutch: {_clutchCurrent*100:F0}%  [C]" +
                         $"Load: {_loadCurrent*100:F0}%  [←][→]  Throttle: {_throttleCurrent * 100:F0}%  Target: {_throttleTarget * 100:F0}%  [W] {(_wKeyHeld ? "BLIP" : "---")}";
                 }
 
@@ -221,6 +231,17 @@ public class Program
             case Keyboard.Key.Right:
                 _loadTarget = MathF.Min(1.0f, _loadTarget + 0.05f);
                 break;
+
+            case Keyboard.Key.E:
+                _scenario.ShiftUp();
+                break;
+            case Keyboard.Key.Q:
+                _scenario.ShiftDown();
+                break;
+
+            case Keyboard.Key.C:
+                _cKeyHeld = true;
+                break;
         }
     }
 
@@ -228,5 +249,8 @@ public class Program
     {
         if (e.Code == Keyboard.Key.W)
             _wKeyHeld = false;
+
+        if (e.Code == Keyboard.Key.C)
+            _cKeyHeld = false;
     }
 }