HTTP Response Freshness Testing

The `fresh` package (version 0.5.2, last published in September 2017) is a minimalist Node.js utility designed to determine if an HTTP response is "fresh" according to client-provided caching headers. Part of the `jshttp` organization, which maintains foundational HTTP middleware and utilities leveraged by frameworks such as Express.js, this library compares a client's `If-None-Match` and `If-Modified-Since` request headers against a server's `ETag` and `Last-Modified` response headers. It returns `true` if the cached response is still valid, indicating a conditional GET request can result in a 304 Not Modified status, or `false` if the cache is stale and a full response is required. Its primary differentiators are strict adherence to HTTP specifications and a focused scope, prioritizing reliability for efficient conditional GET implementations. Given its mature and foundational nature, the package maintains a stable, maintenance-level release cadence with infrequent updates.