fix(desktop): stop prescribing repair and antivirus review for an unverified update

A failed receipt check after a zero-exit update means the updated Desktop build
could not be read, not that the install is damaged. The old copy told users to
repair the installation and review antivirus quarantine, which is destructive
advice for a healthy install (#107685). Say what happened and give the one
non-destructive recovery step.

scripts/desktop-update/windows.ps1

@@ -1633,7 +1633,7 @@ try {
         $verify = Invoke-HermesStep $verifyCommand[0] $verifyArgs 'verify'
         if ($verify.Code -ne 0) {
             $finalCode = 8
-            $finalMsg = "The updated Hermes runtime or Desktop build failed verification. Repair the installation and review antivirus quarantine before retrying."
+            $finalMsg = "Hermes was updated, but the new Desktop build could not be verified. Nothing was removed. If Hermes does not start normally, run 'hermes desktop --force-build' in a terminal to rebuild it."
             Write-HandoffLog $finalMsg
             exit $finalCode
         }