feat(template): reboot VM before final shutdown+snapshot

template/Prepare-WinBuild2025.ps1

@@ -590,6 +590,26 @@ try {
         $choice = Read-Host "[Prepare] Shut down VM and create snapshot '$SnapshotName'? [Y/N]"
         if ($choice -match '^[Yy]') {
 
+            # Reboot VM to flush any pending install state before final snapshot
+            Write-Host "[Prepare] Rebooting VM to finalise installation state..."
+            try {
+                Invoke-Command -Session $session -ScriptBlock { Restart-Computer -Force } -ErrorAction SilentlyContinue
+            }
+            catch { }
+            Remove-PSSession $session -ErrorAction SilentlyContinue
+            $session = $null
+
+            Start-Sleep -Seconds 30  # let WinRM tear down before polling
+            Write-Host "[Prepare] Waiting for guest WinRM to come back after reboot (max 10 min)..."
+            if (-not (Wait-GuestWinRMReady -IP $VMIPAddress -Cred $credential `
+                      -SessionOptions $sessionOptions -TimeoutMin 10)) {
+                throw "[Prepare] Guest did not come back after reboot within 10 min."
+            }
+            Write-Host "[Prepare] Guest WinRM ready after reboot." -ForegroundColor Green
+            $session = New-PSSession -ComputerName $VMIPAddress -Credential $credential `
+                                     -SessionOption $sessionOptions -UseSSL -Port 5986 `
+                                     -Authentication Basic -ErrorAction Stop
+
             # Send graceful shutdown
             Write-Host "[Prepare] Sending graceful shutdown to VM..."
             try {