Fix windev prerelease version during elevation (#4908)

* Fix prerelease elevation cleanup

* Support restricted PowerShell in windev

* Use current PowerShell engine in windev

scripts/main.ps1

@@ -517,7 +517,31 @@ $sync["WPFWin11ISOCleanResetButton"].Add_Click({
     Invoke-WinUtilISOCleanAndReset
 })
 
+function Remove-WinUtilTempScript {
+    <#
+    .SYNOPSIS
+        Removes the temporary script downloaded by windev.ps1.
+
+    .DESCRIPTION
+        Deletes the current script only when it is a winutil-*.ps1 file in
+        the system temporary directory. This preserves normal file-backed
+        and in-memory WinUtil launches.
+    #>
+
+    $scriptPath = $PSCommandPath
+    $tempPath = [IO.Path]::GetFullPath([IO.Path]::GetTempPath()).TrimEnd('\')
+
+    if (
+        $scriptPath -and
+        [IO.Path]::GetDirectoryName($scriptPath) -eq $tempPath -and
+        [IO.Path]::GetFileName($scriptPath) -like 'winutil-*.ps1'
+    ) {
+        Remove-Item -LiteralPath $scriptPath -Force -ErrorAction SilentlyContinue
+    }
+}
+
 # ──────────────────────────────────────────────────────────────────────────────
 
 $sync["Form"].ShowDialog() | out-null
+Remove-WinUtilTempScript
 Stop-Transcript

windev.ps1

@@ -1,5 +1,11 @@
 # Runs the pre-release version of winutil
 
 $latestTag = (Invoke-RestMethod https://api.github.com/repos/ChrisTitusTech/winutil/tags).Name | Select-Object -First 1
-$script = Invoke-RestMethod -Uri https://github.com/ChrisTitusTech/winutil/releases/download/$latestTag/winutil.ps1
-Invoke-Command -ScriptBlock ([scriptblock]::Create($script)) -ErrorAction Stop
+$uri = "https://github.com/ChrisTitusTech/winutil/releases/download/$latestTag/winutil.ps1"
+$scriptPath = Join-Path $env:TEMP "winutil-$latestTag.ps1"
+
+Invoke-WebRequest -Uri $uri -OutFile $scriptPath -UseBasicParsing -ErrorAction Stop
+
+$executable = if ($PSVersionTable.PSEdition -eq 'Core') { 'pwsh.exe' } else { 'powershell.exe' }
+$currentPowerShell = Join-Path $PSHOME $executable
+& $currentPowerShell -ExecutionPolicy Bypass -NoProfile -File $scriptPath