Code Mode generated only a TypeScript SDK and rejected any runtime whose
language was not "typescript". Add py-types.ts (jsonSchemaToPy /
renderToolsSdkPy) and select the SDK-section renderer and the run_code
schema flavor by ctx.codeRuntime.language through two parallel tables
(SDK_RENDERERS, RUN_CODE_FLAVORS), read with Object.hasOwn and failing
loud on a language with no renderer. The tool layer depends only on the
code-runtime seam's language field, so it lands independently of the
Python protocol and backend.