Student page with a standing summary, a class-comparison histogram
(zero-dependency HTML/CSS) with a plain-language fewer/same/more
sentence, opt-out management with withdrawal of future dates, and a
call history that respects the per-course assessment-visibility
setting and never shows pending or skipped calls. Opt-outs validate
against a new per-course class-day schedule (range generator plus
individual add/remove for holidays), since Canvas has no structured
meeting-day data; courses without a schedule fall back to a free date
picker. Dev mode seeds a Tue/Thu pattern.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>