4ca89b9159
- Add helm package type with index.yaml as mutable (TTL-based) and .tgz chart tarballs as immutable - Rewrite chart URLs in index.yaml to serve tarballs via proxy cache - Add text/yaml content-type detection for .yaml/.yml files - Add hashicorp-helm example remote in remotes.yaml - Update README with Helm chart repository proxy section - Add tests for helm mutable patterns and route behaviour