Fetch Metadata Middleware

The `fetch-metadata` package provides Node.js middleware designed for Express and Connect applications to enforce browser Fetch metadata request headers, such as `Sec-Fetch-Site`, `Sec-Fetch-Mode`, and `Sec-Fetch-Dest`. This middleware plays a crucial role in enhancing application security by helping to prevent common web vulnerabilities like Cross-Site Request Forgery (CSRF), Cross-Site Script Inclusion (XSSI), and information leakage attacks, as part of a defense-in-depth strategy. Currently at stable version 1.0.0, it offers a highly configurable API allowing developers to define granular policies for request origins, navigation types, and specific allowed paths. While a specific release cadence isn't published, its initial stable release suggests a focus on reliability for security-critical applications. Its key differentiator lies in its specific focus on these modern browser security headers, providing a ready-to-use solution for integrating these protections into existing Node.js web servers.