U2F API Polyfill

The `u2f-api-polyfill` package provides a JavaScript polyfill that implements the high-level FIDO U2F (Universal 2nd Factor) API for web browsers. It specifically targets environments where `window.u2f` might not natively exist, such as older Chrome versions. Maintained as version 0.4.4, its release cadence is irregular, primarily serving to pull in updates from Google's authoritative `u2f-ref-code` repository. This package acts as a direct port of Google's reference implementation, simplifying its consumption via NPM and eliminating the need for manual synchronization. It is not an independent U2F implementation but a faithful reproduction of Google's code designed for browser compatibility and to expose the global `window.u2f` object. While U2F itself has largely been superseded by the more modern WebAuthn standard, this polyfill remains relevant for maintaining compatibility with existing U2F implementations and legacy applications.