Rust crate builds (rpmbuilder CI) fetch from crates.io directly because artifactapi has no Cargo remote type.
- add `cargo` package type proxying the sparse registry protocol (RFC 2789)
- synthesize `config.json` so `dl` points crate downloads back at the remote
- treat index files as mutable and `crates/*/*.crate` as immutable, fetched from static.crates.io for crates.io
- add a `~/.cargo/config.toml` usage snippet to the UI and a cargo e2e caching case
Reviewed-on: #132
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>
## Summary
- New "Locals" sidebar nav item with list + detail + browse pages
- Remotes page filters out local repos (repo_type=local hidden)
- LocalDetail: simplified view — just name, type, description + "Browse Files" button
- Virtuals: member links resolve to /locals/ or /remotes/ based on repo_type
- Objects page detects context for correct back-navigation
## Test plan
- [ ] Visual check: locals page shows only local repos
- [ ] Remotes page hides local repos
- [ ] Virtual member links point to correct pages
- [ ] Browse files works from local detail page
Reviewed-on: #54
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>