PXE preinstall pipeline + Set-MachineNumber helper for Standard PCs

Adds a local-install pipeline so Standard shopfloor PCs get Oracle, the
VC++ redists (2008-2022), and UDC installed during PXE imaging via Samba
instead of pulling ~215 MB per device from Azure blob over the corporate
WAN. Intune DSC then verifies (already-installed apps are skipped) and
the only Azure traffic on the happy path is ~11 KB of CustomScripts
wrapper polling.

New files:
- playbook/preinstall/preinstall.json — curated app list with PCTypes
  filter and per-app detection rules. Install order puts VC++ 2008
  LAST so its (formerly) reboot-triggering bootstrapper doesn't kill
  the runner mid-loop. (2008 itself now uses extracted vc_red.msi with
  REBOOT=ReallySuppress; the reorder is defense in depth.)
- playbook/shopfloor-setup/Shopfloor/00-PreInstall-MachineApps.ps1 —
  the runner. Numbered 00- so it runs first in the baseline sequence.
  Reads preinstall.json, filters by PCTYPE, polls for completion via
  detection check (handles UDC's hung WPF process by killing it once
  detection passes), uses synchronous WriteThrough logging that
  survives hard reboots, preserves log history across runs.
- playbook/shopfloor-setup/Standard/Set-MachineNumber.{ps1,bat} — desktop
  helper for SupportUser. Reads current UDC + eDNC machine numbers,
  prompts via VB InputBox, validates digits-only, kills running UDC,
  edits both C:\ProgramData\UDC\udc_settings.json and HKLM\…\GE Aircraft
  Engines\DNC\General\MachineNo, relaunches UDC. Lets a tech assign a
  real machine number to a mass-produced PC without admin/LAPS.
- playbook/sync-preinstall.sh — workstation helper to push installer
  binaries from /home/camp/pxe-images/main/ to the live PXE Samba.

Changes:
- playbook/startnet.cmd + startnet-template.cmd — add xcopy to stage
  preinstall bundle from Y:\preinstall\ to W:\PreInstall\ during the
  WinPE imaging phase, gated on PCTYPE being set.
- playbook/pxe_server_setup.yml — create /srv/samba/enrollment/preinstall
  + installers/ directories and deploy preinstall.json there.
- playbook/shopfloor-setup/Run-ShopfloorSetup.ps1 — bump AutoLogonCount
  to 99 at start (defense against any installer triggering an immediate
  reboot mid-dispatcher; final line still resets to 2 on successful
  completion). Copy Set-MachineNumber.{ps1,bat} to SupportUser desktop
  on Standard PCs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

playbook/pxe_server_setup.yml

@@ -313,6 +313,22 @@
         directory_mode: '0755'
       ignore_errors: yes
 
+    - name: "Create preinstall bundle directory on enrollment share"
+      file:
+        path: "{{ item }}"
+        state: directory
+        mode: '0755'
+      loop:
+        - /srv/samba/enrollment/preinstall
+        - /srv/samba/enrollment/preinstall/installers
+
+    - name: "Deploy preinstall.json (installer binaries staged separately)"
+      copy:
+        src: "{{ usb_mount }}/preinstall/preinstall.json"
+        dest: /srv/samba/enrollment/preinstall/preinstall.json
+        mode: '0644'
+      ignore_errors: yes
+
     - name: "Create BIOS update directory on enrollment share"
       file:
         path: /srv/samba/enrollment/BIOS