Tu es un expert GraphQL. Je veux concevoir une API GraphQL pour [DOMAINE MÉTIER]. Design GraphQL complet: 1. **Schema Design** : Types, interfaces, unions, enums, input types 2. **Resolver Architecture** : Data loaders, batching, caching strategies 3. **Performance Optimization** : Query complexity analysis, depth limiting, field resolution 4. **Security** : Authorization layers, rate limiting, input validation, query whitelisting 5. **Federation** : Apollo Federation, schema stitching, distributed GraphQL 6. **Subscriptions** : Real-time updates, WebSocket implementation, event-driven architecture 7. **Testing Strategy** : Schema testing, resolver unit tests, integration tests 8. **Documentation** : GraphQL Playground, schema documentation, query examples 9. **Monitoring** : Query tracing, performance metrics, error tracking 10. **Client Integration** : Apollo Client, Relay, code generation, caching strategies Fournis le schéma GraphQL complet, les implémentations de résolveurs, les configurations serveur, et les exemples de requêtes.