The dev image required the shared glowforge-image base directly, so it
was not a superset of forgefirm-image (it lacked v4l-utils, audit N12).
Require forgefirm-image and add forgectrl + debug tooling on top.
v4l2-ctl (alongside the already-present media-ctl) configures the
imx-media pipeline and grabs raw frames from /dev/video4 while the
gfhardware capture path is ported off the factory NXP V4L2 model.
gfui-client connects to Glowforge's servers; ForgeFIRM replaces it with a
local grblHAL controller (forgectrl). Remove it from the image via an
override, leaving the shared glowforge-image base untouched.