fix: use /proc/misc for device node detection instead of sysfs

The sysfs paths (/sys/devices/virtual/misc/kvm, /sys/class/misc/tun)
don't exist in our minimal kernel config. Use /proc/misc which reliably
lists registered misc devices. Fixes /dev/kvm and /dev/net/tun not being
auto-created.

Bump vz-cli to v0.3.3.

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 = "0.3.2"
+version = "0.3.3"
 description = "CLI for managing containers and macOS VM sandboxes"
 edition.workspace = true
 rust-version.workspace = true

crates/vz-cli/Cargo.toml

@@ -14,10 +14,11 @@ 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
+# Check /proc/misc since sysfs misc class may not exist in minimal configs.
+if grep -q ' kvm$' /proc/misc 2>/dev/null && [ ! -e /dev/kvm ]; then
   /bin/busybox mknod /dev/kvm c 10 232 2>/dev/null || true
 fi
-if [ -e /sys/class/misc/tun ] && [ ! -e /dev/net/tun ]; then
+if grep -q ' tun$' /proc/misc 2>/dev/null && [ ! -e /dev/net/tun ]; then
   mkdir -p /dev/net
   /bin/busybox mknod /dev/net/tun c 10 200 2>/dev/null || true
 fi
@@ -70,10 +71,10 @@ switch_root_into_overlay_rootfs() {
   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 "$ROOTFS/dev/kvm" ]; then
+  if grep -q ' kvm$' /proc/misc 2>/dev/null && [ ! -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 "$ROOTFS/dev/net/tun" ]; then
+  if grep -q ' tun$' /proc/misc 2>/dev/null && [ ! -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