Keep the GOP framebuffer as the floor, make scanout a pluggable backend, and
upgrade to a native virtio-gpu driver when it announces itself (dynamic
hot-attach; GOP stays the fallback for "no driver ever"). v2 builds the shm
cross-process memory capability, shared with the future client-surface path.
Milestones V1 (backend seam) → V6 (resilience + tests), each with a gate.
Daniel Samson