Setup Test is failing

[1-Bart-1]

Ram air kite example is failing

[1-Bort-1]

Fixing the setup-test failure in the audit plot: generated_slices Kulfan-fits an empty deflected .dat (write_section_aero writes all-NaN when a deflection never converges, read_dat_coordinates drops it to empty) and crashes on argmin. I'll treat an empty contour like a missing one - warn and skip the deflection overlay - in ext/VortexStepMethodMakieExt.jl, with a regression test. Builds on main; independent of #301 (the write-side fix for #300).