feat(subscription): gate insurance pages behind "insurance" plan feature

Wrap InsurancePricingPage and ClaimsPage in <FeatureGate feature="insurance">
so direct-URL access is blocked without an active subscription that enables
the feature. Add feature: "insurance" to the sidebar links (doctor/clinic/
secretary sections) so the menu items hide when the plan lacks it.

Make AdminSubscriptionPage feature controls dynamic: derive the plan feature
checkboxes from FEATURE_LABELS (now including "insurance") and switch the Zod
schema to z.record, so adding a feature only touches the label map.

No backend/migration change: plan.features is free-form JSON; existing plans
default to insurance:false and admins enable it per plan.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

assets/admin/pages/InsurancePricingPage.tsx

@@ -1,16 +1,19 @@
 import PageHeader from '../components/ui/PageHeader';
 import TenantInsuranceContracts from '../components/TenantInsuranceContracts';
 import FreeVisitPrice from '../components/FreeVisitPrice';
+import FeatureGate from '../components/ui/FeatureGate';
 
 export default function InsurancePricingPage() {
   return (
-    <div className="fade-in">
-      <PageHeader
-        title="بیمه و قیمت‌گذاری"
-        description="قیمت ویزیت آزاد و قراردادهای بیمه (پایه و تکمیلی)"
-      />
-      <FreeVisitPrice />
-      <TenantInsuranceContracts />
-    </div>
+    <FeatureGate feature="insurance">
+      <div className="fade-in">
+        <PageHeader
+          title="بیمه و قیمت‌گذاری"
+          description="قیمت ویزیت آزاد و قراردادهای بیمه (پایه و تکمیلی)"
+        />
+        <FreeVisitPrice />
+        <TenantInsuranceContracts />
+      </div>
+    </FeatureGate>
   );
 }