feat: automated releases (GoReleaser + GitHub Actions) and -version flag

[fedir]

Summary

Replicates the auto-release setup from the sibling json_encode project so tagged releases of yrank are built and published automatically.

What's added

• .github/workflows/release.yml — on a v* tag push, runs GoReleaser: cross-compiles binaries (linux/darwin/windows × amd64/arm64), publishes a GitHub release with checksums + changelog, and updates the Homebrew tap.
• .github/workflows/ci.yml — on push/PR to master: make vet, make build, make test, plus an offline -local-test smoke run (no API quota).
• .goreleaser.yaml — build/archive/checksum/changelog config + a brews: block publishing a formula to fedir/homebrew-tap.
• -version / -V flag — prints the version and exits. main.go declares var version = "dev", overridden at build time via -ldflags "-X main.version=...".
• Makefile — version injection on build/install, plus release and snapshot targets; clean now also removes dist/.
• Docs — README install-via-Homebrew + a Releases section; refreshed the stale Travis badge to a GitHub Actions CI badge; CLAUDE.md CI/release notes.

How to cut a release

git tag v1.2.3
git push origin v1.2.3

Required secret

The Homebrew formula update needs a HOMEBREW_TAP_TOKEN repository secret with write access to fedir/homebrew-tap (same as json_encode). GITHUB_TOKEN is provided automatically.

Verification

• make build injects the version (confirmed: ./yrank -version → yrank <git-describe>).
• make vet + make test pass with -race.
• GoReleaser config mirrors the working json_encode one; it is validated by the release workflow on the first tag push (goreleaser not installed locally).

🤖 Generated with Claude Code