Give the backups plugin a settings page, and show where a snapshot is

plugins/backups/frontend/routes.js

@@ -12,6 +12,17 @@
  * JWT + a backups.* permission; an anonymous visit would only render errors.
  */
 export default [
+  {
+    // The plugin's five settings had no page at all until this one: the core
+    // settings catalog is a hardcoded list that a plugin cannot extend, so
+    // backups_shareroot and friends were reachable only through the API or a
+    // shell on the server. Paired with get_settings_cards in plugin.py, which
+    // puts the card in the rail - both vanish when the plugin is disabled.
+    path: 'settings/backups',
+    name: 'backups-settings',
+    component: () => import('./views/BackupsSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true, plugin: 'backups' }
+  },
   {
     path: 'backups/asset/:assetid',
     name: 'backups-asset-history',