BeamReconstructor now requires camera/camera_tolerance, threading them
into ModalFitter.fit_auto and PhaseRetriever.retrieve, and uses
GeometryCalibration.effective_pixel_scale for deconvolution instead of
the removed MeasurementPlane.pixel_scale.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Full implementation of Laguerre-Gauss modal reconstruction for gyrotron
beam diagnostics, per the approved design spec, plus tests, docs, and
a runnable end-to-end example.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>