Add size tokens for the 28-36px display/card-title role

[joshestein]

🧩 Summary

The text-size-* scale jumps from lg (24px, fixed) to xl (32px mobile → 48px at md). Nothing covers the 28–36px "card title / app chrome / display" role, so 15 callsites hardcode px. #2826's audit passed all of them as justified carveouts — which is the tell: the tokens are missing, not the discipline.

Hardcoded sites: UnitLayout (32), CourseCompletionSection (28/32), Congratulations (28, 32), CertificateCTA (36), LandingBanner (36), GrantStatsStrip (28), QuoteSection (28/32), EventsSection (32/40), NextDiscussionCard (10, 28).

✅ Definition of done

1. Non-responsive size token(s) covering the 28–36px role, named by role not px
2. All 15 hardcoded text-[Npx] sites re-pointed at tokens (or explicitly justified)
3. GettingStarted.mdx documents when to reach for them vs text-size-lg / xl

Fold in while we're here:

4. Arbitrary leading: EventsSection:68 (leading-[11.2px] lg:leading-[14px]), MobileCourseModal:88 (40px), SideBar:194 (44px), CourseSchedule:167 (24px) — leftovers from Sweep raw components / classes for inconsistencies #2753's DoD
5. Uppercase pill recipe hand-rolled 5× with off-token tracking (tracking-[0.12em] in incubator-week / fieldbuilder-week / career-transition-grant TheWeekSection + LogisticsSection, tracking-[0.14em] in AnnouncementBanner) — excluded from Consolidate ad-hoc eyebrow/label recipes into <Eyebrow> #2795 as non-label uppercase, but it's one recipe copied 5×
6. apps/website/README.md:186,198,205-206 still claims other apps use Roobert / Reckless Neue

📌 Notes / References

Roobert-*.woff2 and RecklessNeue-*.woff2 are still in public/fonts/. Leave them — external consumers load them by URL.