OpenRouter models like Kimi K2.5 return reasoning_details with type
reasoning.text at message level. The pi-ai library only handled
reasoning.encrypted type. This patch stores all reasoning_details
and passes them back in subsequent requests.
Fixes multi-turn tool calls with Kimi K2.5 and similar models.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
