Private Go modules have nowhere to live: goproxy is remote-only, so internal modules need VCS access or a hand-rolled proxy.
- serve local goproxy repos over the GOPROXY protocol (`@v/list`, `@latest`, `.info`/`.mod`/`.zip`) with case-encoded module paths
- accept PUT uploads of `.zip`/`.mod`/`.info` per version; synthesize `.info` when absent
- validate zips with `golang.org/x/mod/zip.CheckZip`, `.mod` module path and `.info` version before storing
- add a ContentValidator hook so providers can check upload bytes
- document publishing in the UI and `docs/goproxy/local.md`; add an e2e-docker case
Reviewed-on: #143
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>
