pmndrs/valtio ? reverse-engineered prompt

Build me a small TypeScript state management library that makes proxy based state simple for both React and plain JavaScript.

I want to create a state object with a proxy helper, update it by mutating it directly anywhere in the app, and then read it in React with a hook that only re renders the parts of the UI that actually changed. It should also work outside React with subscriptions, so I can listen to changes on the whole state or on a specific property. Please include support for a few handy extras like keeping some objects untracked, reading async values in React 19 style, and a way to inspect or debug state changes with devtools.

Make it feel lightweight and easy to use, with a couple of simple examples and tests. If anything is unclear, look up the current docs online first and match the behavior closely.