Metadata Reflection API Polyfill

reflect-metadata provides a polyfill for the Metadata Reflection API, a non-standardized API that gained traction through TypeScript's `--experimentalDecorators` feature. The package is currently at version 0.2.2 and sees infrequent but consistent maintenance, with the most recent patch release (0.2.2) addressing minor fixes. While the original TC39 proposal for Decorator Metadata is no longer being considered for standardization, this package continues to be essential for projects that rely on TypeScript's legacy decorator implementation, such as many Angular or older NestJS applications. Its primary differentiator is providing the `Reflect` global object and its methods (`Reflect.defineMetadata`, `Reflect.getMetadata`, etc.) to enable runtime reflection of metadata attached via decorators, which is not natively supported by standard JavaScript or modern decorator proposals. It offers both a full bundle with internal polyfills for `Map`, `Set`, and `WeakMap` for older runtimes, and a lighter `/lite` version without these internal polyfills.