Native body visual

Add this to an ordinary visual entity under NativeRiderDriver.boardVisualRoot. Set body to a NativeActorPart belonging to that driver's board assembly. The driver supplies its interpolated position and rotation, coherent with the camera. Position/rotation offsets are in body space; visual scale remains authored on the entity. Do not put this component on the physical body itself.

Model and Asset bundle content can be exchanged normally. An animated bundle may keep its own Zero animation components: this binding drives only the visual root, never its bones. It does not alter collision shape, mass or simulation. The current full actor exposes the seven board parts through this presenter.