Add Geofences navigation link for all ADMIN users

Fixed navigation access so that all users with ADMIN role can see
and access the Geofences menu item, not just the 'admin' user.

**Changes:**
- Added "Geofences" to navigation menu
- Set roles: ['ADMIN'] - accessible to all ADMIN users
- Set superAdminOnly: false - not restricted to 'admin' username

Now any user with ADMIN role can:
- Access /admin/geofences (management)
- Access /admin/geofences/events (event history)
- See geofence widget on dashboard
- View geofences on map

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/admin/layout.tsx

@@ -19,6 +19,7 @@ export default function AdminLayout({
   const allNavigation = [
     { name: "Dashboard", href: "/admin", roles: ['ADMIN', 'VIEWER'], superAdminOnly: false },
     { name: "Devices", href: "/admin/devices", roles: ['ADMIN', 'VIEWER'], superAdminOnly: false },
+    { name: "Geofences", href: "/admin/geofences", roles: ['ADMIN'], superAdminOnly: false },
     { name: "MQTT Provisioning", href: "/admin/mqtt", roles: ['ADMIN'], superAdminOnly: false },
     { name: "Setup Guide", href: "/admin/setup", roles: ['ADMIN', 'VIEWER'], superAdminOnly: false },
     { name: "Users", href: "/admin/users", roles: ['ADMIN'], superAdminOnly: false },