STL viewer: model origin doesn't match file — object floats above z=0 #511
Description
Bug
The STL viewer's camera/scene origin doesn't match the file's coordinate system. A model that should be sitting at z=0 appears to be floating in mid-air above the grid plane.
Screenshot
The piece should be resting on the grid at z=0 but is visibly hovering above the origin point where the RGB axes meet.
Expected Behavior
The model should render at its actual coordinates from the STL file. If the model's geometry starts at z=0, it should appear sitting on the grid plane, not floating above it.
Likely Cause
The viewer may be auto-centering the geometry on its bounding box center rather than respecting the file's native origin, or the grid/camera target may be offset from the actual coordinate origin.