macOS: drive the install and all customization from a Recovery "PE", no GUI

Replace the screenshot/OCR/keystroke driving of Apple's Recovery with a
"PE": BaseSystem.dmg (a journaled HFS+ volume, writable from Linux) with one
LaunchDaemon added (makeRecoveryPE) that runs /Volumes/VMIX/run.sh as root at
boot, records the status and powers off. launchd loads it alongside its signed
cache (verified on Tahoe 26.6.2); same idea as AutoNBI/Imagr NetBoot images.

- makeImage: the PE runs vmix-install.sh (erase, installer app, SharedSupport
  pkgdmg, startosinstall). Progress is read from the serial console
  (boot-args serial=3 -v, VMIX-* markers) and screenshots (brightness only).
  Fully offline; prepare now takes ~5 min instead of ~10.
- customizeImage: boots the PE with the image attached and runs the template
  offline against the mounted System/Data volumes; OpenCore ScanPolicy
  restricted to HFS+/SATA so only the PE can boot. One PE boot ~30 s. The
  installed macOS is never booted for customization, so nothing depends on
  launchd/BTM approval or a first-boot agent (removed).
- templates rewritten for offline use: generalize creates the user with
  dscl -f (admin, home, auto-login kcpassword, Setup Assistant suppression,
  hostname, locale, timezone, keyboard type, container resize); remote-access,
  no-updates, performance edit the target's plists.
- makeBootDisk: build-time OpenCore variant (serial console, ScanPolicy).
- vm-driver.py rewritten: passive observation only (serial markers, kernel
  boots, panics, brightness), disk+serial-aware hang watchdog, reboot-death
  reset, halt/loginwindow detection. No OCR/tesseract.
- OpenCore: four SMBIOS DIMMs for MacPro7,1 (no "Memory Modules
  Misconfigured" warning).
- tools/soak.sh: repeatability harness.

Verified on daku: base install 23 min end to end; basic + generalize in three
~30 s PE boots; the result auto-logs into the desktop with the created user.

Root cause of the "first-boot hang" (from the serial log): the guest's restart
path panics (IOPlatformHaltRestartAction -> AppleSMC, SMCWDT smcWriteKey
kSMCBadCommand, nested panic) because the pinned OSX-KVM Lilu disables itself
on macOS 26, so VirtualSMC never loads. Handled by the driver (reset within
60 s); kext update to follow.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XsESshRCoBoUVWV9qKURUF

lib/images/macos/helpers/makeBootDisk.nix

@@ -0,0 +1,29 @@
+# OpenCore boot disk for build-time boots, derived from an image's ESP
+# (makeOpenCore output) with build-only settings: extra boot-args (serial
+# console, verbose) and optionally an OpenCore ScanPolicy so that only the PE
+# (an HFS+ volume on SATA) is bootable — the build never lands on the wrong OS.
+{ pkgs, lib, ... }:
+{ esp, bootArgs ? null, scanPolicy ? null, name ? "boot" }:
+pkgs.runCommand "${name}-bootdisk" {
+  nativeBuildInputs = with pkgs; [ python3 mtools dosfstools gptfdisk ];
+} ''
+  cp -r ${esp}/EFI EFI
+  chmod -R u+w EFI
+  python3 - <<'PY'
+  import plistlib
+  p = 'EFI/OC/config.plist'
+  cfg = plistlib.load(open(p, 'rb'))
+  nv = cfg['NVRAM']['Add']['7C436110-AB2A-4BBB-A880-FE41995C9F82']
+  ${lib.optionalString (bootArgs != null) ''nv['boot-args'] = ${builtins.toJSON bootArgs}''}
+  ${lib.optionalString (scanPolicy != null) ''cfg['Misc']['Security']['ScanPolicy'] = ${toString scanPolicy}''}
+  plistlib.dump(cfg, open(p, 'wb'))
+  print('boot-args:', nv['boot-args'], 'ScanPolicy:', cfg['Misc']['Security']['ScanPolicy'])
+  PY
+  mkdir -p $out
+  truncate -s 64M $out/boot.img
+  sgdisk -n 1:2048:0 -t 1:EF00 -c 1:EFI $out/boot.img >/dev/null
+  SECTORS=$(( 64*1024*1024/512 - 2048 - 34 ))
+  mkfs.vfat -F 32 -n OPENCORE --offset 2048 $out/boot.img $(( SECTORS / 2 )) >/dev/null
+  mcopy -i $out/boot.img@@1M -s EFI ::
+  mdir -i $out/boot.img@@1M ::EFI/OC >/dev/null
+''