GraphQL Schema Design

Design a GraphQL schema for {{domain}} supporting {{requirements}}. Define the types, queries, and mutations with clear naming, how to model relationships, pagination, error handling, and nullability decisions, how to avoid the N+1 query problem with data loaders, and authorization at the field level. Provide the schema outline and the reasoning. Note the common GraphQL mistakes (over-fetching enabled by clients, N+1 queries, exposing too much) and how to keep the schema secure and performant. Stack: {{stack}}.