Agent Skills: homebrew-formula-authoring

Create, update, validate, and submit Homebrew formulae (homebrew-core, built from source). Use when the user mentions a Homebrew formula, Homebrew/homebrew-core, adding/updating a formula, brew create, building from source, a build system in a brew context (cargo/rust, go, cmake, meson, autotools/configure, make, python virtualenv, node/npm, ruby gem), resource blocks, depends_on/keg_only/uses_from_macos, the mandatory test do block, bottles, livecheck, brew bump-formula-pr, or when asked to run brew audit --new / brew test / brew style for a formula. For macOS GUI apps and prebuilt binaries use the homebrew-cask-authoring skill instead.