Allowing convex radius 0 on a box shape with half extent 0

Also fixed a div by zero in that case when debug drawing the supporting face

See https://github.com/godotengine/godot/issues/101893

Jolt/Physics/Collision/Shape/BoxShape.cpp

@@ -59,7 +59,7 @@ BoxShape::BoxShape(const BoxShapeSettings &inSettings, ShapeResult &outResult) :
 {
 	// Check convex radius
 	if (inSettings.mConvexRadius < 0.0f
-		|| inSettings.mHalfExtent.ReduceMin() <= inSettings.mConvexRadius)
+		|| inSettings.mHalfExtent.ReduceMin() < inSettings.mConvexRadius)
 	{
 		outResult.SetError("Invalid convex radius");
 		return;

Jolt/Physics/Collision/Shape/ConvexShape.cpp

@@ -505,7 +505,7 @@ void ConvexShape::DrawGetSupportingFace(DebugRenderer *inRenderer, RMat44Arg inC
 		SupportingFace face = ftd.first;
 
 		// Displace the face a little bit forward so it is easier to see
-		Vec3 normal = face.size() >= 3? (face[2] - face[1]).Cross(face[0] - face[1]).Normalized() : Vec3::sZero();
+		Vec3 normal = face.size() >= 3? (face[2] - face[1]).Cross(face[0] - face[1]).NormalizedOr(Vec3::sZero()) : Vec3::sZero();
 		Vec3 displacement = 0.001f * normal;
 
 		// Transform face to world space and calculate center of mass