[BUG]UI renders multiple times on single prompt input

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Single prompt input causes the entire Claude Code UI to render 13+ times. The complete interface (header, prompt, response, input bar) repeats down the terminal on each render.

Potentially related: #45499

What Should Happen?

Single render of prompt and response.

Error Messages/Logs

Steps to Reproduce

1. Launch Terminal.app (fresh window, 80×24)
2. Run claude (or alias)
3. Enter "hello"
4. Observe: UI renders 13+ times

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

Opus 4.6

Claude Code Version

Opus 4.6

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_