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>
