Add free/paid feature gating (Role Editor, Activity Log, DB Explorer,

Analytics, White Label, remote site switcher are paid)

- New License class is the single gate every paid feature checks —
  today it's a placeholder (any non-empty license_key counts as active)
  since there's no license server yet, but every gated feature already
  funnels through it so swapping in real remote validation later won't
  touch anything else.
- Role Editor, Activity Log, and Database Explorer stay registered/
  capability-checked as before, but render an UpgradeNotice screen
  instead of the real feature when unlicensed (and skip loading the
  real JS bundle/REST data). Menu Creator, Admin Notices, Comments,
  and Plugins stay free.
- Analytics' tracking hooks and REST endpoint, and White Label's
  favicon/rename/text-replace hooks, simply don't register without a
  license. Settings fields for both stay visible/editable either way.
- Remote site switcher gated alongside its existing capability check.
- Sidebar shows a small lock badge on locked Aurora nav items; the
  Dashboard's Analytics tab shows the same upgrade prompt when locked.
- Fixed an unrelated bug surfaced while testing Role Editor: RolesData's
  REST callback called get_editable_roles() without loading
  wp-admin/includes/user.php first, which REST requests don't get for
  free (only real wp-admin page loads do) — 500'd every time.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/src/pages/dashboard/Dashboard.vue

@@ -13,13 +13,14 @@ import ActiveUsers from './cards/ActiveUsers.vue';
 import DeviceUsage from './cards/DeviceUsage.vue';
 import Engagement from './cards/Engagement.vue';
 import TopList from './cards/TopList.vue';
+import UpgradeNotice from '../_shared/UpgradeNotice.vue';
 
 const props = defineProps({
   serverData: { type: Object, required: true },
 });
 
 const { data, loading, load } = useDashboardData(props.serverData);
-const { data: analytics, load: loadAnalytics } = useAnalyticsData(props.serverData);
+const { data: analytics, error: analyticsError, load: loadAnalytics } = useAnalyticsData(props.serverData);
 
 // Date range — default last 7 days, with simple presets.
 const today = new Date();
@@ -107,6 +108,12 @@ onMounted(() => reload(range.value[0], range.value[1]));
       </div>
     </div>
 
+    <UpgradeNotice
+      v-else-if="analyticsError"
+      feature="Analytics"
+      description="Upgrade to Aurora Admin Pro to unlock first-party visitor analytics for this dashboard."
+    />
+
     <div v-else class="dash__grid">
       <div class="dash__cell" style="grid-column: span 8">
         <PageViews :data="analytics ? analytics.pageViews : {}" />