osmatrix-ci

Run a repository's GitHub Actions workflows locally with act before pushing, including OS matrices - ubuntu legs on the host's Docker, windows/macos legs inside local VMs. Plan, run, poll, read the logs of failed legs, re-run a single leg, and report what a local run cannot reproduce. Use when asked to "run CI locally" or "test the Windows/macOS job", when a GitHub Actions leg failed on another OS, or when a change touches workflow files or OS-specific code (paths, shells, line endings, native deps).