Clarify active Windows client architecture

apps/windows-client/scripts/install-control-app.ps1

@@ -0,0 +1,79 @@
+param(
+  [string]$InstallRoot = "C:\Program Files\VpnProxy\ControlApp",
+  [string]$DataRoot = "C:\ProgramData\VpnProxy",
+  [switch]$PlanOnly,
+  [switch]$Force
+)
+
+$ErrorActionPreference = "Stop"
+
+function New-Result {
+  param(
+    [bool]$Success,
+    [string]$Action,
+    [bool]$Changed,
+    [string]$Message,
+    [hashtable]$Details = @{}
+  )
+
+  [ordered]@{
+    success = $Success
+    action = $Action
+    changed = $Changed
+    message = $Message
+    details = $Details
+  } | ConvertTo-Json -Depth 6
+}
+
+function Test-IsAdministrator {
+  $identity = [Security.Principal.WindowsIdentity]::GetCurrent()
+  $principal = [Security.Principal.WindowsPrincipal]::new($identity)
+  $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
+}
+
+function Ensure-Directory {
+  param([string]$Path)
+  if (-not (Test-Path -LiteralPath $Path)) {
+    New-Item -ItemType Directory -Path $Path -Force | Out-Null
+    return $true
+  }
+  return $false
+}
+
+try {
+  $details = @{
+    installRoot = $InstallRoot
+    dataRoot = $DataRoot
+    planOnly = [bool]$PlanOnly
+  }
+
+  if ($PlanOnly) {
+    New-Result -Success $true -Action "install-control-app" -Changed $false -Message "Control App install plan is ready." -Details $details
+    exit 0
+  }
+
+  if (-not (Test-IsAdministrator)) {
+    New-Result -Success $false -Action "install-control-app" -Changed $false -Message "Administrator rights are required." -Details $details
+    exit 1
+  }
+
+  $changed = $false
+  $changed = (Ensure-Directory -Path $InstallRoot) -or $changed
+  $changed = (Ensure-Directory -Path (Join-Path $DataRoot "config")) -or $changed
+  $changed = (Ensure-Directory -Path (Join-Path $DataRoot "state")) -or $changed
+  $changed = (Ensure-Directory -Path (Join-Path $DataRoot "generated")) -or $changed
+
+  $markerPath = Join-Path $InstallRoot "install-control-app.marker.json"
+  if ((-not (Test-Path -LiteralPath $markerPath)) -or $Force) {
+    @{ component = "control-app"; installedAt = (Get-Date).ToString("o") } |
+      ConvertTo-Json -Depth 4 |
+      Set-Content -LiteralPath $markerPath -Encoding UTF8
+    $changed = $true
+  }
+
+  $details.markerPath = $markerPath
+  New-Result -Success $true -Action "install-control-app" -Changed $changed -Message "Control App directories are installed." -Details $details
+} catch {
+  New-Result -Success $false -Action "install-control-app" -Changed $false -Message $_.Exception.Message
+  exit 1
+}