Builds end-to-end type-safe tRPC APIs: routers, Zod procedures, dual Next.js App Router context factories, protected middleware, and subscriptions. Use when scaffolding tRPC in a TypeScript monorepo or migrating REST/GraphQL incrementally inside one repo. Not for OpenAPI/REST-only backends or GraphQL schema-first stacks. Do not share one context factory between fetch Request handlers and RSC callers.
