Spamming server errors during subagent execution

### Describe the bug

There are a lot of transient server errors, especially during subagent tasks. Every time I run anything using fleet or anything that requires a subagent task, I'll get 10-15 or more copies of "Response was interrupted due to a server error. Retrying...".

Nothing seems to be affected, and the /tasks read-only view does not show any issues.

### Affected version

GitHub Copilot CLI 1.0.74-0

### Steps to reproduce the behavior

_No response_

### Expected behavior

It would be nice if the messages could be collapsed into one, for example, that updates a disruption count in place, or even just a little "Unstable connection, 5 retries" at the bottom somewhere.

### Additional context

_No response_

Start by reproducing a fleet or subagent task on GitHub Copilot CLI 1.0.74-0 and observe the retry messages alongside the /tasks read-only view. Trace where repeated "Response was interrupted due to a server error. Retrying..." messages are emitted; done when transient retries are represented by one collapsed message or disruption count without changing task behavior.

Written by the indexing model from the issue text.