- Added `TestConvertOpenAIChatCompletionsResponseToOpenAIResponses_CompletedOmitsTopLevelOutputText` to ensure `output_text` is excluded in streamed responses.
- Added `TestConvertOpenAIChatCompletionsResponseToOpenAIResponses_ToolCallCompletedOmitsTopLevelOutputText` to validate behavior during tool call completions.
- Introduced `TestConvertOpenAIChatCompletionsResponseToOpenAIResponsesNonStream_OmitsTopLevelOutputText` to confirm the omission of `output_text` in non-streamed responses.
- Expanded test coverage to ensure consistency with native OpenAI responses.