Evicting or deleting a local RPM removed the local_files row but left its
rpm_metadata behind, so generated repodata kept listing a package that no
longer exists. Deletes now run a provider cleanup hook symmetric to the
existing upload hook.
- add PostDeleteHook and MetadataDeleter provider interfaces, plus a
DeleteRPMMetadata DB method
- implement AfterDelete in the RPM provider to drop the metadata row
- route both local delete paths (evictLocal and the files handler) through
a shared deleteLocalFile helper that removes the file then runs the hook
- cover the cleanup with a dockerised test
## Summary
- Upload RPMs to local repos, metadata parsed async via cavaliergopher/rpm
- Repodata (repomd.xml, primary/filelists/other.xml.gz) generated on-demand from DB — nothing stored in S3
- RPM provider implements LocalUploader, PostUploadHook, and LocalIndexer
- New rpm_metadata table for parsed RPM header data (name, version, deps, etc.)
- New provider interfaces: PostUploadHook, BlobReader, MetadataStore, RPMMetadataReader
## Test plan
- [x] Upload cowsay RPM from epel → async metadata parse confirmed in logs
- [x] repomd.xml generated with correct hashes → primary.xml.gz has correct metadata
- [x] `dnf install` from local repo: download + install successful
- [x] Bad file rejection (.txt → 400), overwrite rejection (409)
Reviewed-on: #53
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>