Tags: rolze/mex

Sem & Mex 0.2.1

release: bump to 0.2.0

- Add sem build jobs (default + vips variant) to release workflow
- Restructure release.yml: build-mex, build-sem, build-sem-vips, create-release
- Update INSTALL.md with pre-built binary instructions for mex and sem

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

minor cleanup before first release