Install FieldCraft

Drag FieldCraft.app onto Applications.

If this build is not notarized (the release notes say so), macOS blocks the first launch:
right-click FieldCraft.app in Applications and choose Open, then Open again. Or run

    xattr -dr com.apple.quarantine /Applications/FieldCraft.app

Updating: quit FieldCraft, drag FieldCraft.app from this disk image onto Applications and
choose Replace.

The command-line tool, fieldcraft-cli, is a separate download (fieldcraft-cli-*-macos-*.zip).
