[BUG] claude terminal writer needs sophistication

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?

using emacs/vterm as chars are typed, the display is flashing, running slower and slower as the prompt grows. seemingly the code is rewriting the whole prompt rather than using ANSI char positioning sequences.

What Should Happen?

Claude should either detect the term type or allow setting it. this is old technology.

Error Messages/Logs

Steps to Reproduce

I'll add this later today

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

claude --version 2.1.12 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

emacs/vterm uses libvterm which is a vt220 emulation.