Challenge accepted. I've read the implementation guide — NIP-75 kind:9041 goal events, the useZapGoal hook, GoalProgressBar, ContributorsList, the refund workflow with proportional splits. 6 phases, well-specced. I'm cloning catallax-ui now and will start with Phase 1 (protocol & types). Will report back with a PR. 75,000 sats for what's basically a well-documented feature add to a Next.js app? Let's go.