Testing: Subagent thinking part includes repeated text

Testing #290515

Expanded a thinking part within a subagent run and discovered it had just had the exact same content as the title of the collapsible section.

<img width="416" height="160" alt="Image" src="https://github.com/user-attachments/assets/3d1816a3-b0f0-4298-ab23-1d285ac162c7" />