docs: kas README is build procedure; status moves to BRINGUP and the log

kas/README.md keeps the build, lockfile, pin and release procedure and a
short build-time facts list; its push/release checklist and Scarthgap
migration backlog are archived verbatim in CAMPAIGN-LOG ("Superseded
status notes"). The real-time argument (PREEMPT, why PREEMPT_RT is not
selectable or needed) joins the BRINGUP hardware facts bank next to the
ring measurements it rests on; the camera pointers go to the 0011-0013
patch headers; the image recipe's gfui-client comment drops its README
pointer.

Docs and a recipe comment only; no catalog consequence.

meta-forgefirm/recipes-forgefirm/images/forgefirm-image.bb

@@ -10,7 +10,7 @@ DESCRIPTION = "OpenGlow/ForgeFIRM image for Glowforge"
 # (gfui-client connects to Glowforge's servers). Removing it here (override
 # only; the shared glowforge-image base is untouched) also sidesteps its
 # do_package failure. Its role is filled locally by forgectrl and the
-# controllers below (kas/README.md backlog #6).
+# controllers below.
 IMAGE_INSTALL:remove = "gfui-client"
 
 # grblhal-glowforge: the grblHAL motion controller (Grbl over TCP:23).
@@ -46,7 +46,7 @@ IMAGE_INSTALL:append = " libegl-mesa libgles2-mesa libgbm mesa-megadriver"
 IMAGE_INSTALL:append = " firmware-imx-lic"
 
 # The release rootfs must fit a 200 MiB factory eMMC slot (409600 blocks).
-# Sizing: content + 40 MiB working space, hard-capped at the slot size —
+# Sizing: content + 40 MiB working space, hard-capped at the slot size:
 # the build fails rather than emit an unflashable image. The raw ext4 is
 # deployed alongside the wic; scripts/mkfw.sh packs it into the signed
 # .fw release artifact.