Turnstone container-VM: podman image -> boco qcow2 boot

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.

start-turnstone.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+# VM entrypoint, exec'd as PID 1 by /boco/init (image runs as root).
+# Starts sshd for ops access, prepares virtiofs share ownership, then
+# drops to the marvin user and execs turnstone-server.
+set -euo pipefail
+
+export HOME=/home/marvin
+
+# sshd: host keys baked per-boot, ops channel on guest port 22
+ssh-keygen -A
+mkdir -p /run/sshd
+/usr/sbin/sshd
+
+# virtiofs shares appear root-owned (host dir is owned by the host user,
+# which maps to guest root) — hand them to marvin so the server and
+# agent tools can write. Also ensure ~/.config stays marvin-owned:
+# boco-init creates mount-point dirs as root, and rootless podman
+# refuses to run when $HOME/.config is not owned by the user.
+mkdir -p /var/lib/turnstone /home/marvin/.config
+chown marvin:marvin /var/lib/turnstone /home/marvin/.config || true
+chown -R marvin:marvin /home/marvin/work || true
+
+# Rootless container networking (pasta/slirp4netns) needs TUN access;
+# the guest has no udev, so devtmpfs leaves it root-only.
+if [ ! -e /dev/net/tun ]; then
+  mkdir -p /dev/net
+  [ -c /dev/net/tun ] || mknod /dev/net/tun c 10 200
+fi
+chmod 666 /dev/net/tun || true
+
+# Seed the admin account (no-op when the user already exists — password
+# is ignored on promotion). Runs as marvin so DB files it creates are
+# marvin-owned. Override via image env or boot cmd:
+#   boco boot ... --cmd 'ADMIN_PASSWORD=... start-turnstone.sh'
+ADMIN_USER="${ADMIN_USER:-marvin}"
+ADMIN_PASSWORD="${ADMIN_PASSWORD:-marvin-turnstone}"
+if [ "$ADMIN_PASSWORD" = "marvin-turnstone" ]; then
+  echo "start-turnstone: WARNING — default admin password in use; set ADMIN_PASSWORD to change it"
+fi
+setpriv --reuid=marvin --regid=marvin --init-groups \
+  /usr/local/bin/turnstone-admin create-admin \
+    --username "$ADMIN_USER" \
+    --password "$ADMIN_PASSWORD" \
+  || echo "start-turnstone: admin seeding failed (continuing)"
+
+# NOTE: turnstone reads $HOME/.config/turnstone/config.toml as marvin
+exec setpriv --reuid=marvin --regid=marvin --init-groups \
+  /usr/local/bin/turnstone-server --host 0.0.0.0 --port 8080