The scan already treats fov_circular==0 as "disabled" and defaults to
it, but the GUI spinbox floor of 0.1 made 0 unreachable. Lower the
floor to 0.0 and label the field so the meaning is explicit.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The stage_x_rot/fovy and stage_y_rot/fovx comparisons look swapped,
but are correct: alpha bakes in a fixed ~90 deg mechanical offset
between the piezo axes and the angle=0 beam frame that fovx/fovy are
defined in, so stage_x_rot actually tracks the beam-frame y-extent.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>