Frontier CLI 5.9.2 offline bundle (customer-controlled networks, no internet, no login).
Verify:  cosign verify-blob --key cosign.pub --signature SHA256SUMS.sig --insecure-ignore-tlog=true SHA256SUMS
         sha256sum -c --ignore-missing SHA256SUMS
Linux/macOS/WSL: FRONTIER_LOCAL_DIR=$PWD sh install.sh
Windows:         $env:FRONTIER_LOCAL_DIR=$PWD; .\install.ps1
Debian/Ubuntu:   sudo apt install ./frontier_*_<arch>.deb     RHEL/Rocky: sudo dnf install ./frontier-*.rpm
Then: frontier workstation enroll --help
