Controller promoted to canonical driver repo grblHAL-glowforge

The step backend now lives in github.com/ScottW514/grblHAL-glowforge
  (grblHAL driver convention: core submodule, driver.c HAL, board header).
  Add build-glowforge.sh, update the BRINGUP runbook (no -t throttle,
  EEPROM path, kill-before-scp, producer stats line, reset/disconnect
  semantics), and teach bench_m2.py to parse the F: status field (no
  spindle registered = no FS: field). Settings-write crash fix is
  upstream as grblHAL/core PR 999.

scripts/bench/build-glowforge.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+# Cross-compiles grblHAL-glowforge (the canonical driver repo) for the
+# factory board, borrowing the Yocto cross toolchain from the ulfius work
+# directory. Run from PowerShell: wsl -d forge-yocto -- bash <path>.
+set -e
+TC=/home/builder/dev/openglow-forgefirm/forgefirm/build/tmp/work/cortexa9t2hf-neon-fslc-linux-gnueabi/ulfius/2.7.15
+export PATH="$TC/recipe-sysroot-native/usr/bin:$TC/recipe-sysroot-native/usr/bin/arm-fslc-linux-gnueabi:$PATH"
+cd /home/builder/dev/openglow-forgefirm/grblHAL-glowforge
+rm -rf build-arm
+cmake -B build-arm \
+  -DCMAKE_SYSTEM_NAME=Linux -DCMAKE_SYSTEM_PROCESSOR=arm \
+  -DCMAKE_C_COMPILER=arm-fslc-linux-gnueabi-gcc \
+  -DCMAKE_BUILD_TYPE=None \
+  "-DCMAKE_C_FLAGS=--sysroot=$TC/recipe-sysroot -mthumb -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9 -O1 -g" \
+  "-DCMAKE_EXE_LINKER_FLAGS=--sysroot=$TC/recipe-sysroot" \
+  > /tmp/cmake-gf.log 2>&1
+cmake --build build-arm -j8 > /tmp/gfbuild.log 2>&1 || { tail -30 /tmp/gfbuild.log; exit 1; }
+echo BUILD-OK
+file build-arm/grblHAL_glowforge 2>/dev/null || ls build-arm/