docs: describe the firmware that exists; ship the NXP firmware EULA

README: replace the stalled REST/GUI roadmap with what the firmware does -
GRBL mode over TCP for LightBurn/UGS/cncjs, optional cloud mode, the web
control panel, cameras, A/B install beside the factory firmware - plus the
supported hardware incl. the 8 MP camera limitation and a real roadmap.

kas/README: xvclk is the board's 24 MHz oscillator; the pin/push rule covers
every source repo; camera and motion sections are hardware-validated, with the
OV8856 caveat spelled out; the device-tree item closes with the control_12v
residue named; forgectrl is the machine-services daemon with two supervised
controllers.

LIGHTBURN.md: drop the pre-first-light status line.

BUILD.md: state the NXP firmware licensing and where the EULA lives on the
machine. The image now installs firmware-imx-lic, so the EULA text ships beside
the VPU/EPDC blobs it covers; a bbappend declares that package at parse time,
which is what makes it installable from an image recipe.

BUILD.md

@@ -70,6 +70,15 @@ kas lock kas/forgefirm-glowforge.yml
 See [`kas/README.md`](kas/README.md) for details, the container-build option,
 and the Scarthgap migration backlog.
 
+## Third-party firmware licensing
+
+The i.MX6 BSP installs NXP firmware blobs (VPU, EPDC) that are distributed
+under NXP's firmware EULA. The build config accepts it
+(`ACCEPT_FSL_EULA = "1"`), and the image ships the license text alongside the
+blobs at `/usr/share/licenses/firmware-imx/EULA` — keep it there in any
+redistributed image. The SDMA firmware comes from `linux-firmware`, which
+carries its own license package.
+
 ## Write to an SD card
 
 ```console