- OS-dependent sysexts (e.g., docker-flatcar, containerd-flatcar, podman, zfs, nvidia) are now cryptographically signed using dm-verity roothash signatures. This enables stricter sysext policies via systemd-sysext and provides a foundation for verifying user-provided extensions in future releases. The format changed from squashfs to erofs-based Discoverable Disk Images (DDI). OEM sysexts (e.g., oem-azure, oem-gce) are now also signed and built during the image phase to ensure consistent signing with the same ephemeral key. ([scripts#3162](https://github.com/flatcar/scripts/pull/3162))
