RPM package for Fedora/RHEL/openSUSE

[vmvarela]

Description

Create an .rpm package so Fedora, RHEL, and openSUSE users can install sql-pipe via rpm -i or from a COPR/YUM repository.

Acceptance Criteria

• Generate .rpm packages for x86_64 and aarch64 architectures
• Package includes the binary, man page, and license
• Package metadata is correct (name, version, summary, license, URL)
• Installation via rpm -i sql-pipe-<version>.<arch>.rpm works
• .rpm artifacts are uploaded to GitHub Releases by the CI workflow
• README updated with RPM installation instructions

Notes

• Consider using nfpm or rpmbuild with a .spec file to generate the package
• The man page is already built as sql-pipe.1.gz in the release workflow
• Packages should follow RPM naming conventions: sql-pipe-<version>-1.<arch>.rpm