The [`files` field](https://docs.npmjs.com/cli/v10/commands/npm-publish#files-included-in-package)
controls what files get included in the published package.
This PR specifies the `files` field on our publishable packages to only
include the `dist` directory, since we don't need to ship any types or
sourcemaps with 3 of them.
react-compiler-runtime is a runtime package which has sourcemaps, so we
also include the `src` directory in the published package.
Also fixes an invalid version range for the react peer dependency in
react-compiler-runtime, tested that it works via https://semver.npmjs.com/
ghstack-source-id: 12b36c203fc9fd8d72a1995fb3fba2312de4aa51
Pull Request resolved: https://github.com/facebook/react-forget/pull/2965
- Updated all directly defined dependencies to the latest React 19 Beta
- `package.json`: used `resolutions` to force React 19 for `react-is` transitive dependency
- `package.json`: postinstall script to patch fbt for the React 19 element Symbol
- Match on the message in Snap to exclude a React 19 warning that `act` should be imported from `react` instead (from inside `@testing-library/react`)
- Some updated snapshots, I think due to now recovering behavior of `useMemoCache`, please review.
In a next step, we can do the following. I excluded it since it from here as it made the PR unreviewable on GitHub.
- Snapshots now use `react/compiler-runtime` as in prod, so the different default in Snap is no longer needed.
