MeasurementPlane now carries a z_tolerance (uniform tolerance mechanism)
instead of the removed pixel_scale/viewing_angle_deg fields.
ReconstructionResult.pointing_angle_deg becomes horizontal/vertical fields
to match the beam's two independent tilt degrees of freedom.
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>