Promotes 0.1.6 to the current stable Walter On-Prem release
Fixes the initial GHCR access check so installs without existing registry auth prompt for credentials instead of appearing to hang
Keeps the on-prem installer and smoke coverage aligned with the fast registry probe path
Operator notes
bin/walter-onprem upgrade resolves to 0.1.6 for existing 0.1.x installs
bin/walter-onprem upgrade --to 0.1.6 pins this release explicitly
Fresh curl -fsSL https://onprem.walterops.com/install/install-walter.sh | bash installs should now fall through to the GHCR login prompt quickly on hosts that are not already authenticated