Unify Go and TypeScript client analysis

[meoyawn]

Summary

• analyze request bodies and responses once in a language-neutral client contract
• emit straight-line required JSON requests and conditional optional-body headers
• use canonical TypeScript body parameters and remove redundant Go bodyless-status booleans
• reject unsupported request bodies consistently in both emitters
• regenerate Go and TypeScript golden clients

Verification

• task check
• full Listenbox monorepo task check
• autoreview: no accepted/actionable findings