UDC: correct CLI arg signature to compact site + dash-prefixed machine#

UDC_Setup.exe and UDC.exe expect:
  UDC_Setup.exe WestJefferson -7605

Not the spaced-quoted positional pair we'd been passing:
  UDC_Setup.exe "West Jefferson" 7605

The wrong format meant UDC ignored both args, fell back to defaults
(Site=Evendale, MachineNumber=blank). Combined with the kill-after-detect
window, neither value got persisted to udc_settings.json regardless of
whether UDC.exe was given time to write.

Changes:
- preinstall.json: UDC InstallArgs now "WestJefferson -9999"
- 00-PreInstall-MachineApps.ps1: site override now matches/replaces
  the compact 'WestJefferson' token (not 'West Jefferson') and uses
  siteNameCompact from site-config; targetNum extraction regex updated
  to '-(\d+)$' for the new dash-prefix format
- Update-MachineNumber.ps1: UDC.exe relaunch now passes positional
  compact-site + dash-prefixed number instead of -site/-machine flags

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

playbook/preinstall/preinstall.json

@@ -138,7 +138,7 @@
       "Name": "UDC",
       "Installer": "UDC_Setup.exe",
       "Type": "EXE",
-      "InstallArgs": "\"West Jefferson\" 9999",
+      "InstallArgs": "WestJefferson -9999",
       "KillAfterDetection": true,
       "DetectionMethod": "Registry",
       "DetectionPath": "HKLM:\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\UDC",