Replace the tsgo native preview with typescript@7.0.2 and port the check scripts to the TS 7 API. Target ES2024, drop useDefineForClassFields: false and unused decorator options, and enable verbatimModuleSyntax. Replace tsx with node plus the source resolver hook, passed to --import as a file URL.
closes#9965
Keep protocol payloads transport-opaque and validate service calls, state snapshots, updates, and errors at Chord boundaries. Ensure successful OpenAI Responses messages remain strict JSON so terminal Transcript updates reach clients.