Single-curve variant of f2b — production trace only, no replay overlay
and no uniform reference. Cleaner for boss-meeting/talk slides where the
extra context is noise. The combined three-curve figure is unchanged.
scripts/plot_session_skew_cdf.py: split into plot_combined +
plot_production_solo helpers; one run emits both PNGs.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
