SIA v1.7.2 — steady first light

The cockpit and bar now keep the last validated healthy generation visible during routine status refreshes, eliminating the transient installation-check flash.

First-light safety remains fail-closed. Install and update now restart the Omarchy shell while the gate is still closed, require the live cockpit to attest the exact source release, revalidate the installed tree, and only then publish ready.

Validation: QML lint, Omarchy plugin validation, the complete 864-test suite, and a live all-frame cockpit/status-publication check.