Function load_cached_spec 

pub fn load_cached_spec<P: AsRef<Path>>(
    cache_dir: P,
    spec_name: &str,
) -> Result<CachedSpec, Error>

Loads a cached OpenAPI specification from the binary cache with optimized version checking.

This function uses a global cache metadata file for fast version checking before loading the full specification, significantly improving performance.

After version checks pass, validates the spec file fingerprint (mtime, size, content hash) against the cached metadata. If the spec file has been modified since caching, returns Error::cache_stale with a suggestion to reinitialize.

Arguments

• cache_dir - The directory containing cached spec files
• spec_name - The name of the spec to load (without binary extension)

Returns

• Ok(CachedSpec) - The loaded and deserialized specification
• Err(Error) - If the file doesn’t exist, deserialization fails, or cache is stale

Errors

Returns an error if the cache file doesn’t exist, deserialization fails, or the spec file has been modified since the cache was built