Gate both kiosks behind a device token, and make an unreachable setting a test failure

plugins/usb/frontend/views/USBKiosk.vue

@@ -133,7 +133,7 @@
 
 <script setup>
 import { ref, computed, onMounted, onBeforeUnmount, nextTick } from 'vue'
-import api, { settingsApi } from '@/api'
+import api, { settingsApi, claimKioskToken, KIOSK_TOKEN_KEYS } from '@/api'
 import TouchKeypad from '@/components/TouchKeypad.vue'
 import { filterdrives } from '../drivefilter'
 
@@ -150,6 +150,7 @@ const entryInput = ref(null)
 let resetTimer = null
 
 onMounted(async () => {
+  claimKioskToken(KIOSK_TOKEN_KEYS['/usb/kiosk/'])
   // The kiosk ships off. Reading the flag turns "everything 404s" into a screen
   // that says so - a kiosk merely switched off must not look broken.
   try {