Migrating a legacy React app from webpack to Vite

The codebase was old. React 16 with class components everywhere. React Router v3 with routes-as-children. A webpack 4 config that had been edited by a dozen people over five years and contained loaders nobody could explain. The dev server took 45 seconds to come up. Hot reload was 8 seconds on a good day, 20 on a bad one. The production build was 6 minutes. CI deploys took 14 minutes end to end. I'd been dismissing Vite for two years. "Webpack works." It did work. It was also bleeding an hour a