Add reliable built-in demo mode

SUB Control/run_spoofer.ps1

@@ -0,0 +1,20 @@
+$ErrorActionPreference = "Stop"
+$projectRoot = Split-Path -Parent $MyInvocation.MyCommand.Path
+Set-Location -LiteralPath $projectRoot
+
+$existingListener = Get-NetTCPConnection -LocalPort 5760 -State Listen -ErrorAction SilentlyContinue | Select-Object -First 1
+if ($existingListener) {
+    $existingProcess = Get-CimInstance Win32_Process -Filter "ProcessId=$($existingListener.OwningProcess)" -ErrorAction SilentlyContinue
+    Write-Host ""
+    Write-Host "The simulator is already LISTENING on tcp:127.0.0.1:5760." -ForegroundColor Green
+    Write-Host "Process: $($existingListener.OwningProcess) $($existingProcess.Name)"
+    Write-Host "Leave that simulator running and select 'Simulator (TCP 5760)' in SUB Control."
+    Write-Host ""
+    exit 0
+}
+
+if (Test-Path -LiteralPath ".venv\Scripts\python.exe") {
+    & .venv\Scripts\python.exe -u fc_spoofer.py @args
+} else {
+    & python -u fc_spoofer.py @args
+}