feat: add Homebrew distribution via GoReleaser

[jflowers]

Context

Replicator is replacing the Node.js Swarm plugin (opencode-swarm-plugin / cyborg-swarm) as the multi-agent coordination tool for the Unbound Force ecosystem. It needs to be installable via brew install unbound-force/tap/replicator.

Changes Required

GoReleaser config (.goreleaser.yaml)

• Add GoReleaser v2 config following the pattern in unbound-force/unbound-force/.goreleaser.yaml
• Configure cross-platform builds (darwin-arm64, darwin-amd64, linux-arm64, linux-amd64)
• Configure Homebrew cask/formula publishing to unbound-force/homebrew-tap
• Set binary name to replicator
• Add macOS quarantine removal hook (same as unbound-force binary)

GitHub Actions release workflow

• Add .github/workflows/release.yml triggered on version tags
• Use GoReleaser GitHub Action for automated releases

Makefile updates

• Add release target for local testing
• Add install target that builds and installs to GOPATH/bin

Acceptance Criteria

• brew install unbound-force/tap/replicator installs the binary
• replicator version prints the correct version after install
• replicator serve starts the MCP server
• Cross-platform builds available in GitHub Releases

Related

• unbound-force/unbound-force (pending issue) depends on this for uf setup Homebrew install path