v2.1.0 — Korean-only, editorial redesign, calendar & check-ins

Highlights

• Korean-only app — bilingual support removed by design; dates pinned to ko-KR
• Editorial design system — paper/ink/persimmon tokens, big-type headlines, hairline lists
• 캘린더 — month history view with tinted trial windows and reaction/check-in dots
• 이상 없음 check-ins — one-tap "no reaction observed" logging during a trial
• Fixed 3-day observation window, aligned with pediatric guidance (KDCA, 대한소아청소년과학회, NHS)
• Demo mode (EXPO_PUBLIC_DEMO=1) — 46 days of realistic seeded history for demos
• Branding — traffic-light app icon, paper splash, light/dark logo
• CI — typecheck + 42 Jest tests on every push

Full design document: docs/design-spec.md