Chat responses duplicated multiple times in UI

Question

## Description

Responses from Claude are appearing duplicated 5+ times in the chat UI. The response is generated once (no extra token cost), but the display renders it multiple times in sequence.

## Steps to reproduce

Occurs during an active coding session. The duplication seems to happen after tool calls complete and Claude returns a text response — the same response block appears repeated multiple times in the conversation view.

## Environment

- Platform: macOS (Darwin 23.4.0)
- Shell: zs