Mirrors the kiosk-firmware admin shape one-for-one against OS RAUC
bundles:
/admin/os-updates release list, yank
/admin/os-updates/rollouts rollout list + create
/admin/os-updates/rollouts/:id/state pause/resume/complete
/admin/kiosks/:id/os-update per-kiosk channel + pin
Templates: OsUpdatePage, OsUpdateRolloutsPage, KioskOsUpdatePanel.
KioskOsUpdatePanel is rendered next to the existing KioskFirmwarePanel
on the kiosk detail page so OS + app state sit side-by-side. The
"how bundles get here" sidebar on the list page documents the four
GitHub secrets needed (signing cert/key + autoimport URL/key) so a
new operator doesn't have to dig through scripts/ to find them.
Nav gains an OS Updates entry between Firmware and Labels. Activates
on activeNav="os-updates".
Repo + import endpoint already existed (audit confirmed earlier). All
admin routes use them as-is.
