StyleX Unplugin Bundler Plugin

@stylexjs/unplugin is a universal bundler plugin built upon the `unplugin` abstraction, designed to compile StyleX CSS at build time. It aggregates CSS from all transformed modules within a project and injects the resulting styles into an existing CSS asset produced by the bundler. If no such asset is found, it emits a stable fallback CSS file. Currently at version 0.17.6, the package is actively maintained and supports various bundlers including Vite, Rollup, Webpack, Rspack, and esbuild. Its key differentiators lie in providing a unified, declarative API across these diverse build environments, ensuring consolidated and deterministic StyleX output. Furthermore, it offers specialized development helpers via virtual modules like `virtual:stylex:runtime` and `/virtual:stylex.css` to facilitate efficient hot CSS reloads during development, simplifying the integration of StyleX into modern JavaScript build pipelines.