PullImage now checks the embedded imagecat catalog first. If the
ref matches a catalog entry, it takes the bundle path:
1. Fetch the .tar.zst bundle into a staging dir (rootfs.ext4 +
manifest.json).
2. Strip manifest.json (staging-only metadata).
3. Stage kernel/initrd/modules alongside rootfs.ext4.
4. Publish the staging dir and upsert the image row.
Bundle rootfs is already flattened + ownership-fixed + agent-
injected at build time, so the daemon-side work is strictly I/O —
no flatten, no mkfs, no debugfs.
Kernel resolution in the bundle path: --kernel-ref > entry.kernel_ref
> --kernel/--initrd/--modules.
If the ref doesn't match a catalog entry, PullImage falls through
to the existing OCI path unchanged (extracted into pullFromOCI).
New test seam: d.bundleFetch. Six unit tests cover happy path,
--kernel-ref override, existing-name rejection, kernel-required
error, fetch-failure cleanup, and the catalog → OCI fallthrough.
CLI help updated: image pull now documents both forms and takes
<name-or-oci-ref> instead of requiring an OCI ref.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>