improve formatting of invocations streaming responses

A response from `invoke` displays like this: 

<img width="2458" height="863" alt="Image" src="https://github.com/user-attachments/assets/ec5e050d-189c-4f29-a878-f9962f76d859" />

We should format like:

<img width="2296" height="1262" alt="Image" src="https://github.com/user-attachments/assets/e0b2a445-0d7a-457c-af25-dd09742ca46b" />