scripts/build-release.sh builds reproducible linux/amd64 and linux/arm64 archives with SHA256SUMS; the release workflow runs it on a v* tag after vet, tests and govulncheck, and publishes the release. The README now covers what the tool is, what it does step by step, why each decision is made, how to deploy and run a mail host, the security model, and troubleshooting. -h exits 0.