Repository archives are always named `<project>-<ref>-<sha>` even if
the ref is a commit. A consequence of always including the sha even
for tags is that packaging a release is more difficult because both
the ref and sha must be known by the packager.

- add `<project>/-/archive/<ref>/<filename>.<format>` route using the
`-` separator to prevent namespace collisions. If the filename is
`<project>-<ref>` or the ref is a sha, the sha will be omitted,
otherwise the default filename will be used.
- deprecate previous archive route `repository/<ref>/archive`