GitHub Actions is GitHub's built-in CI/CD system — it spins up a fresh virtual machine, runs whatever commands you tell it to, and tears the machine down when it's done. It supports Linux, Windows, and macOS runners. The macOS runners are the interesting part here, because they're actual macOS machines with Xcode's command-line build tools available, which means they can build and sign iOS apps — not just run tests. The headline rule: public repos are free On a public repository,...