fix: proper shell quoting in vz run and auto-create /dev/kvm, /dev/net/tun

- Replace hand-rolled shell_escape() with shell_words::quote() so that
  `vz run -- sh -c 'echo hello'` correctly preserves multi-word arguments
  when passed through /bin/sh -c.

- Auto-create /dev/kvm and /dev/net/tun in the init script when the kernel
  supports them but devtmpfs doesn't populate the nodes. Applies to both
  initramfs-only and overlay rootfs (chroot) boot paths.

Bump vz-cli to v0.3.2.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: lightsofapollo

crates/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "vz-cli"
-version = "0.3.1"
+version = "0.3.2"
 description = "CLI for managing containers and macOS VM sandboxes"
 edition.workspace = true
 rust-version.workspace = true

crates/vz-cli/Cargo.toml

@@ -258,7 +258,14 @@ pub async fn cmd_run(args: DevRunArgs) -> anyhow::Result<()> {
     let container_id = resolve_container(&mut client, &sandbox_id).await?;
 
     // Build the shell command with env vars and working directory.
-    let shell_command = args.command.join(" ");
+    // Each argument is shell-quoted so that multi-word args (e.g. `sh -c 'echo hello'`)
+    // are preserved when the command string is passed through `/bin/sh -c`.
+    let shell_command = args
+        .command
+        .iter()
+        .map(|arg| shell_words::quote(arg).into_owned())
+        .collect::<Vec<_>>()
+        .join(" ");
     let mut env_map = config.env.clone();
 
     // Ensure HOME is always set — many tools (rustup, npm, etc.) depend on it.
@@ -283,7 +290,7 @@ pub async fn cmd_run(args: DevRunArgs) -> anyhow::Result<()> {
 
     let env_prefix: String = env_map
         .iter()
-        .map(|(k, v)| format!("export {}={}", k, shell_escape(v)))
+        .map(|(k, v)| format!("export {}={}", k, shell_words::quote(v)))
         .collect::<Vec<_>>()
         .join("; ");
 
@@ -866,12 +873,3 @@ fn parse_memory(raw: Option<&str>) -> anyhow::Result<u64> {
     }
 }
 
-fn shell_escape(s: &str) -> String {
-    if s.chars()
-        .all(|c| c.is_alphanumeric() || c == '_' || c == '-' || c == '/' || c == '.' || c == ':')
-    {
-        s.to_string()
-    } else {
-        format!("'{}'", s.replace('\'', "'\\''"))
-    }
-}

crates/vz-cli/src/commands/dev.rs

@@ -11,6 +11,17 @@ mount -t tmpfs tmpfs /tmp
 
 mkdir -p /run /mnt/rootfs /mnt/merged
 
+# Create device nodes that devtmpfs may not auto-populate.
+# /dev/kvm: needed for nested virtualization (Firecracker, QEMU).
+# /dev/net/tun: needed for tap networking (Firecracker guest NICs).
+if [ -e /sys/devices/virtual/misc/kvm ] && [ ! -e /dev/kvm ]; then
+  /bin/busybox mknod /dev/kvm c 10 232 2>/dev/null || true
+fi
+if [ -e /sys/class/misc/tun ] && [ ! -e /dev/net/tun ]; then
+  mkdir -p /dev/net
+  /bin/busybox mknod /dev/net/tun c 10 200 2>/dev/null || true
+fi
+
 # Optional runtime binary share (host-provided youki artifact).
 mkdir -p /mnt/oci-runtime-bin
 
@@ -58,6 +69,15 @@ switch_root_into_overlay_rootfs() {
   mount -t devtmpfs devtmpfs "$ROOTFS/dev" || true
   mount -t tmpfs tmpfs "$ROOTFS/tmp" || return 1
 
+  # Create device nodes that devtmpfs may not auto-populate in the chroot.
+  if [ -e /sys/devices/virtual/misc/kvm ] && [ ! -e "$ROOTFS/dev/kvm" ]; then
+    /bin/busybox mknod "$ROOTFS/dev/kvm" c 10 232 2>/dev/null || true
+  fi
+  if [ -e /sys/class/misc/tun ] && [ ! -e "$ROOTFS/dev/net/tun" ]; then
+    mkdir -p "$ROOTFS/dev/net"
+    /bin/busybox mknod "$ROOTFS/dev/net/tun" c 10 200 2>/dev/null || true
+  fi
+
   # Mount cgroup2 for OCI container runtime (youki) support.
   mkdir -p "$ROOTFS/sys/fs/cgroup"
   mount -t cgroup2 none "$ROOTFS/sys/fs/cgroup" || true