Implements a complete billing system with:
Backend (Django):
- New billing app with models: Feature, Plan, PlanVersion, PlanFeature,
Subscription, AddOnProduct, AddOnFeature, SubscriptionAddOn,
EntitlementOverride, Invoice, InvoiceLine
- EntitlementService with resolution order: overrides > add-ons > plan
- Invoice generation service with immutable snapshots
- DRF API endpoints for entitlements, subscription, plans, invoices
- Data migrations to seed initial plans and convert existing tenants
- Bridge to legacy Tenant.has_feature() with fallback support
- 75 tests covering models, services, and API endpoints
Frontend (React):
- Billing API client (getEntitlements, getPlans, getInvoices, etc.)
- useEntitlements hook with hasFeature() and getLimit() helpers
- FeatureGate and LimitGate components for conditional rendering
- 29 tests for API, hook, and components
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
