feat: Show full tool call response

After expanding a tool call to view its output, only the last few lines are visible. In many cases those lines don’t contain any useful information, which makes it hard to understand what the tool returned.

<img width="966" height="337" alt="Image" src="https://github.com/user-attachments/assets/ed998b45-3a81-4ada-bee2-4d1af5340652" />