Add SystemTest Agent and Controller

SystemTest-Controller/start_controller.ps1

@@ -0,0 +1,53 @@
+param(
+    [string]$HostName,
+    [int]$Port = 0
+)
+
+$ErrorActionPreference = "Stop"
+Set-Location -LiteralPath $PSScriptRoot
+
+if ($HostName) {
+    $env:CONTROLLER_HOST = $HostName
+}
+if ($Port -gt 0) {
+    $env:CONTROLLER_PORT = [string]$Port
+    if (-not $env:CONTROLLER_PUBLIC_BASE_URL) {
+        $env:CONTROLLER_PUBLIC_BASE_URL = "http://127.0.0.1:$Port"
+    }
+}
+
+$pythonExe = $null
+$pythonArgs = @()
+
+if ($env:PYTHON_EXE -and (Test-Path -LiteralPath $env:PYTHON_EXE)) {
+    $pythonExe = $env:PYTHON_EXE
+}
+
+if (-not $pythonExe) {
+    $bundledPython = Join-Path $env:USERPROFILE '.cache\codex-runtimes\codex-primary-runtime\dependencies\python\python.exe'
+    if (Test-Path -LiteralPath $bundledPython) {
+        $pythonExe = $bundledPython
+    }
+}
+
+if (-not $pythonExe) {
+    $pythonCommand = Get-Command python -ErrorAction SilentlyContinue
+    if ($pythonCommand) {
+        $pythonExe = $pythonCommand.Source
+    }
+}
+
+if (-not $pythonExe) {
+    $pythonCommand = Get-Command py -ErrorAction SilentlyContinue
+    if ($pythonCommand) {
+        $pythonExe = $pythonCommand.Source
+        $pythonArgs = @('-3')
+    }
+}
+
+if (-not $pythonExe) {
+    throw "Python 3 was not found. Install Python 3, set PYTHON_EXE, or add Python to PATH."
+}
+
+& $pythonExe @pythonArgs -m app
+exit $LASTEXITCODE