Libraries with issues

[eps1lon]

• @react-spring/web ships global JSX namespace
• Emotion: andarist is informed. Will be fixed in next major that uses new React 19 APIs.
• @headlessui/react declares components as forwardref render functions (see react.dev: Compat with React 19 types reactjs.org#1)
• styled-jsx ships global JSX namespace: next.js: Compat with React 19 types  next.js#1
• framer-motion ships global JSX namespace, ReactHTML, and DetailedHTMLFactory: React Spectrum: Compat with React 19 types react-spectrum#1
• lucide-react uses ReactSVG
• React aria: Compatibility with React 19 types adobe/react-spectrum#6276
• react-redux: Compatibility with React 19 types reduxjs/react-redux#2162
• react-router: Compatibility with React 19 types remix-run/react-router#11506
• MUI: Compatibility with React 19 types mui/material-ui#42032

Libraries will be informed once RC is ready.