tailcat (Tailscale data plane, no control plane) forwards the VM's
web UI and SSH ports to another machine via a stable saved-key
address; outbound-only, so it works through the nested slirp NAT.
Arch image with turnstone (venv), dev toolkit, rootless podman; boots
via boco (virtiofs shares, direct UID mapping for nested virtiofs).
sshd ops channel + turnstone-server as guest marvin; state (SQLite db,
config, work) on host shares; LLM via the TensorX OpenAI-compatible
gateway (https://api.tensorx.ai/v1), reachable from the guest through
both slirp layers with no relay.
marvin