Function serve_path 

pub fn serve_path(path: &str, if_none_match: Option<&str>) -> BundleResponse

Dispatch a request to the bundle registry by path + optional If-None-Match.

Returns a framework-agnostic BundleResponse. Mount via the framework adapter (ferro::bundle::Bundle::serve) on /bundles/{filename} and each alias path.

Order of checks (D-03): 1) alias → 301 redirect, 2) bundle → 304 fast-path on ETag match else 200 with bytes, 3) 404.