[BUG] Startup banner layout breaks in CJK environments due to U+2026 width handling

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?

The current startup ASCII banner uses the character U+2026 (HORIZONTAL ELLIPSIS, “…”).

This character is classified as a Unicode East Asian Ambiguous (A) width character. In many CJK environments (Japanese, Chinese, Korean), terminals render ambiguous-width characters as width 2.

As a result, on CJK users' terminals, the ellipsis is often displayed as a double-width character. This causes the startup banner layout to break due to incorrect column alignment.

Problem

• U+2026 is an East Asian Ambiguous character.
• In CJK terminal environments, ambiguous characters are frequently rendered as width 2.
• The banner layout assumes width 1.
• Therefore, the banner becomes visually misaligned for CJK users.

What Should Happen?

Request

I would like to request replacing U+2026 with a character that is guaranteed to be narrow (width 1), such as:

• ASCII periods (.)
• ASCII underscore (_)
• middle dot U+00B7 (·)
• Or another explicitly half-width character

Using a strictly narrow character would ensure consistent rendering across both non-CJK and CJK terminal environments.

Error Messages/Logs

Steps to Reproduce

npx @anthropic-ai/claude-code

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.114

Platform

Other

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

This issue is a continuation of #26337 and #35560, which was closed due to inactivity.