Move the camera between ticks

CameraController::step eases the camera's position, orbit angles and zoom a
share k (0.4) of the way to their targets at each tick; between ticks, the
adapter's getCameraTransform (its entry in CameraController's exported vtable,
replaced after checking it) sets them 1 - (1 - k)^fraction of the way for IMVU's
code to make the transform from, then puts them back. k is read from the
constant CameraController::step uses, checked to be referenced there.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

adapter/scene_hooks.hpp

@@ -9,6 +9,8 @@
 // - ModelInstance::render's call to updateCalSkeleton, which poses the model before it's drawn: between ticks, the
 //   model is posed at the time between them (its animations' times moved on by the fraction of a frame since the
 //   tick; Cal3D poses between keyframes), then its animations are put back as they were.
+// - CameraController::getCameraTransform (its exported vtable): between ticks, the camera where its easing toward its
+//   target has brought it since the tick.
 
 #include <cstdint>