improved weapon system and cleaner weapon setup

systems/head/HeadSystem.cs

@@ -184,6 +184,15 @@ public partial class HeadSystem : Node3D
         _camera.Fov = Mathf.Lerp(_camera.Fov, targetFov, (float) delta * FovChangeSpeed);
     }
 
+    public void HideWeapon()
+    {
+        _fpRig.Visible = false;   
+    }
+    public void ShowWeapon()
+    {
+        _fpRig.Visible = true;
+    }
+
     public float ComputeCameraInclineFactor(Vector3 direction)
     {
         var forward = GetForwardHorizontalVector().Normalized();