Add super/jump admin, per-host connection tracking; move stats to Audit

- app_super_admin (cross-app, also recognized by sso-manager-node/proxy)
  and a new app_jump_admin group are added to conf.auth: super admins are
  full admins here same as app_sso_admin; jump admins get audit page/data
  access without other admin rights (isJumpAdmin/requireJumpAdmin in
  middleware/auth.js, wired into routes/api.js's audit-data gate and the
  /audit page's client-side forceLogin -- previously the page shell
  rendered for any logged-in user, only the data was gated).
- Dashboard: moved the stat boxes and Top hosts/Top users cards to the
  Audit page (audit is now the admin-facing metrics home; dashboard stays
  focused on "hosts I can reach"). Renamed "All hosts" to "My hosts".
- Host list now shows Last connection/Last failed connection columns and
  highlights rows green (live session, from session_registry) or yellow
  (most recent attempt failed) -- backed by new per-host last-success/
  last-fail timestamps in models/metrics.js, populated by ssh_server.js
  (which now attributes grammar/TUI connect failures to the resolved host
  when one was found, not just aggregate counters) and surfaced through
  GET /api/user/hosts (routes/user.js).

nodejs/utils/ui.js

@@ -37,6 +37,6 @@ module.exports = {
 	nav: [
 		{href: '/dashboard', icon: 'fa-solid fa-gauge-high', label: 'Dashboard', groups: []},
 		{href: '/sessions', icon: 'fa-solid fa-plug-circle-bolt', label: 'Sessions', groups: []},
-		{href: '/audit', icon: 'fa-solid fa-clipboard-list', label: 'Audit', groups: ['admin']},
+		{href: '/audit', icon: 'fa-solid fa-clipboard-list', label: 'Audit', groups: ['admin', 'app_jump_admin']},
 	],
 };