Shopfloor scripts: em-dash to hyphen, add positional Level param

Replace em-dash characters with plain hyphens across the 5 shopfloor
setup scripts (avoids cp1252 mojibake in .bat files and keeps the
PowerShell sources consistent). Also adds [Parameter(Position=1)] to
Write-PreInstallLog so the Level argument can be passed positionally.

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

playbook/shopfloor-setup/Standard/Set-MachineNumber.ps1

@@ -1,4 +1,4 @@
-# Set-MachineNumber.ps1 — Update UDC + eDNC machine number on a Standard shopfloor PC
+# Set-MachineNumber.ps1 - Update UDC + eDNC machine number on a Standard shopfloor PC
 #
 # Purpose:
 #   Both UDC and eDNC use the same per-machine identifier ("Workstation Number" /
@@ -135,7 +135,7 @@ if (Test-Path $udcExePath) {
 $summary = ($results -join "`n") + "`n`nTo apply eDNC changes, restart any running DncMain.exe."
 [System.Windows.Forms.MessageBox]::Show(
     $summary,
-    "Set Machine Number — Done",
+    "Set Machine Number - Done",
     [System.Windows.Forms.MessageBoxButtons]::OK,
     [System.Windows.Forms.MessageBoxIcon]::Information
 ) | Out-Null