Client-Side Module Marker

The `client-only` package is a specialized marker module within the React Server Components (RSC) ecosystem, primarily used in frameworks like Next.js App Router. Its sole purpose is to indicate to the build system that a module and all its transitive dependencies are intended exclusively for client-side execution. It doesn't export any functions or values, acting purely as a side-effect import. When a module imports `client-only`, compatible bundlers and frameworks will enforce that this module is never included in a server bundle, providing build-time errors for misuse. This package, currently at version `0.0.1` and infrequently updated due to its static nature, complements `server-only` to clearly define server-client boundaries in a hybrid rendering environment. Its key differentiator is its explicit, declarative way of preventing accidental server-side imports of client-specific code, which helps avoid issues like 'window is not defined' errors during server rendering.