feat(billing): implement tenant subscription entitlements system (milestones 0-6)

control/ui/src/app/layout.tsx

@@ -16,9 +16,11 @@ const navItems: NavItem[] = [
   { label: 'Roles & Permissions', to: '/roles-permissions' },
   { label: 'Config', to: '/config' },
   { label: 'Definitions', to: '/definitions' },
+  { label: 'Documents', to: '/documents' },
   { label: 'Scale & Placement', to: '/scale-placement' },
   { label: 'Deployments', to: '/deployments' },
   { label: 'Observability', to: '/observability' },
+  { label: 'Platform Drift', to: '/drift' },
   { label: 'Audit Log', to: '/audit-log' },
   { label: 'Settings', to: '/settings' },
 ]