Typescript

This gives Claude strict TypeScript patterns for building type-safe systems, with a heavy focus on runtime validation through Zod schemas, branded types to prevent ID mixing, and discriminated unions for state machines. It's built around TDD workflow and includes compiler configs that turn on every strict flag. The guide assumes you're working on something like the JARVIS AI assistant it references, but the patterns for API boundaries, generic HUD components, and exhaustive switch statements apply to any TypeScript project where you want the type system doing real work. The performance section on memoization and the "no any escape hatch" principle show this is aimed at production codebases, not prototypes.