gemini: Send thought signatures back to API (#32064)

This is a follow-up to:
- #31925 
- #31902

Release Notes:

- Support Gemini thought signatures
41e9f3148cOleksiy Syvokon committed on 6/16/2025, 2:24:44 PM· committed by GitHubparentb749d93
1 file changedLine totals unavailable