fix(decommission): smoke :8091 via curl --noproxy; idempotent F2

The F3 smoke false-failed: system VPN proxy swallows Invoke-WebRequest
to localhost (wiki bug #7), returning empty -> gate aborted before E/M.
Verified out-of-band: :8091 -> HTTP 200 (real stostayer.old page), so
the repoint actually succeeded. Switched smoke to curl.exe --noproxy.
Made F2 idempotent (only repoint if still localhost) so re-runs don't
clobber the original localhost backup.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/decommission-windows-recovery-host/finish-elevated.ps1

@@ -31,8 +31,9 @@ $cn = New-Object System.Data.SqlClient.SqlConnection $verify; $cn.Open()
 $c = $cn.CreateCommand(); $c.CommandText = "SELECT DB_NAME()"; $db = $c.ExecuteScalar(); $cn.Close()
 Write-Host "  verify snolla->VDS stostayer OK (db=$db)" -ForegroundColor Green
 
-# ---------- F2: repoint web.config ----------
+# ---------- F2: repoint web.config (idempotent) ----------
 Write-Host "`n=== F2. repoint stostayer.old web.config ===" -ForegroundColor Cyan
+if ($src -match '(?i)Data Source=localhost') {
   Copy-Item $wcPath "$wcPath.bak-pre-vds-$(Get-Date -Format yyyyMMdd)" -Force
   $xml = [xml](Get-Content $wcPath)
   $node = $xml.configuration.connectionStrings.add | Where-Object { $_.name -eq 'MoreThenCmsEntities' }
@@ -41,14 +42,16 @@ if ($new -notmatch 'TrustServerCertificate') { $new = $new.TrimEnd(';') + ';Trus
   $node.connectionString = $new
   $xml.Save($wcPath)
   Write-Host "  web.config -> mssql.kzntsv.site (backup alongside)" -ForegroundColor Green
+} else { Write-Host "  already pointed at VDS - skip (original backup preserved)" -ForegroundColor Green }
 
-# ---------- F3: restart pool + smoke ----------
+# ---------- F3: restart pool + smoke (proxy-bypassed) ----------
 Write-Host "`n=== F3. restart pool stostayer.old + smoke :8091 ===" -ForegroundColor Cyan
 Restart-WebAppPool -Name 'stostayer.old'
 Start-Sleep -Seconds 5
-$code = try { (Invoke-WebRequest "http://localhost:8091/" -UseBasicParsing -TimeoutSec 30).StatusCode } catch { $_.Exception.Response.StatusCode.value__ }
+# system VPN proxy swallows localhost (wiki bug #7) -> curl.exe --noproxy bypasses it
+$code = (& curl.exe -s -o NUL -w "%{http_code}" --noproxy "*" --max-time 30 http://localhost:8091/)
 Write-Host "  :8091 -> HTTP $code"
-if ((-not $code) -or ($code -ge 500)) {
+if ((-not ($code -match '^\d+$')) -or ([int]$code -eq 0) -or ([int]$code -ge 500)) {
   Write-Error "stostayer.old returned '$code' - repoint FAILED. Leaving MSSQL untouched. Rollback: restore web.config.bak-pre-vds-*."
   return
 }