OpenAI / anthropic / gemini request converter

This converter normalizes your body into one internal turn list and rebuilds it for the other two APIs, so what you get is the honest intersection, not a promise of parity. Lost means the target has no equivalent at all. Changed means the value moved or was reshaped, like temperature clamped to Anthropic's range or consecutive turns merged. Added means the target requires a field the source never stated, usually Anthropic's max_tokens at 1024. Info covers reminders, like Gemini carrying the model in the URL. Check the generated ids and the clamped values before you send anything.