- Added draggable handles for the torso and head to the test harness.
- Updated `IK_HANDLE_PATHS` to include new entries for "Head" and "Torso".
- Implemented distinct colors for the torso (magenta) and head (yellow) markers.
- Added a visual aid (aim line) to indicate the head's LookAt target direction.
- Ensured that dragging the torso moves only the torso marker, allowing for limb stretching towards stationary targets.