CatchUp, a cross-platform group scheduling

CatchUp, a cross-platform group scheduling app (client prototype): a React Native organizer app plus a zero-install PWA that guests open straight from an SMS link, both running on one Convex real-time backend. Group convergence runs through a 5-stage weighted scoring engine that blends availability, priorities, time-of-day preferences, and live penalties for bad weather and travel distance. Also in there: a from-scratch WCAG accessibility harness and 157 test files. The live demo is the organizer app with the backend deliberately disconnected.