feat: add htoprc for incus containers (#14)

- htop shows offline cpus with lxd
- change htop to show cpu average (instead of all)
- add network/disk io

Reviewed-on: https://git.query.consul/unkin/packer-images/pulls/14

ci/build.sh

@@ -19,8 +19,8 @@ fi
 if [ -n "$images_changes" ]; then
   echo "Changes detected in images/. Running specific 'make' commands..."
 
-  # Extract unique paths for `make` commands
-  TARGETS=$(echo "$images_changes" | sed -E 's|images/||; s|/[^/]+$||' | sort -u)
+  # Extract unique image targets (keep only up to 3 directory levels)
+  TARGETS=$(echo "$images_changes" | sed -E 's|^images/([^/]+/[^/]+/[^/]+).*|\1|' | sort -u)
 
   # Prioritize base images first
   BASE_TARGETS=$(echo "$TARGETS" | grep '/base$' || true)