TypeSpec code review

Review the diff against the rules this project actually enforces. Every comment must point at a concrete problem in the changed code and cite the rule or code that makes it a problem — if you cannot cite it, do not post it.

Scope

Applies to the whole repository: the pnpm workspace packages (packages/compiler, packages/http, packages/openapi3, packages/json-schema, packages/versioning, …), the language emitter packages (packages/http-client-{csharp,java,python}), .chronus/changes/**, and their tests.

For the language emitter packages, §1 (tier policy) does not apply to their internal APIs and their own rules in .github/instructions/*.instructions.md take precedence — but §2 (changeset), §3 (compiler API usage) and §4 (tests) apply everywhere.

Out of scope — do not comment on: