The directory-only keep-list (drivers/virtio, drivers/firmware) missed
virtio_net.ko which lives in drivers/net/, virtio_blk in drivers/block/,
and virtio-rng in drivers/char/hw_random/. Switch to find-based approach:
collect all virtio*.ko* and *fw_cfg*.ko* regardless of subdirectory, then
restore them into their original relative paths under kernel/.
Artifacts now: 42 MiB (vmlinuz 11 MiB + initramfs 31 MiB), gate passes.
joshsiv-mulga
ddaaf36942