[TUI] CJK ambiguous-width characters (① ② ③) overlap the following text on Windows Terminal

Environment

• kimi-code 0.38.0 native Windows CLI
• Windows Terminal on Windows 11 (zh-CN locale; East Asian ambiguous-width chars render as 2 cells)

Repro

1. Have the assistant output text containing circled digits, e.g. ①你的 GitHub 真身是 wubing-wx；②鼠标点击定位那条
2. In the TUI, each circled digit overlaps the character that follows it (screenshot available on request).

Analysis

U+2460 CIRCLED DIGIT ONE (and siblings) is East Asian Ambiguous width: Windows Terminal in a CJK locale renders it 2 cells wide, while the TUI's width model appears to count it as 1 cell — every subsequent glyph on the line is drawn one cell too far left, producing the overlap. Suggest honoring the terminal's ambiguous-width behavior (or defaulting ambiguous=2 in CJK locales).

Workaround

Avoid ambiguous-width characters in assistant output (use 1. instead of ①).

Start in the TUI's character-width and rendering path, using the Windows Terminal reproduction with U+2460 circled digits in a zh-CN locale. Determine how ambiguous-width characters are measured and make the rendered text stop overlapping the following glyph while preserving normal-width behavior.