Cursor does not adjust for double-width glyphs

In Rio:

<img width="70" height="45" alt="Image" src="https://github.com/user-attachments/assets/a2b9972f-a172-4189-972a-0e35a5eb390e" />

In Alacritty:

<img width="57" height="36" alt="Image" src="https://github.com/user-attachments/assets/b90d1258-1251-48c7-9f17-84dc49033569" />

rioterm 0.4.12 on MacOS 26.5.2 (via homebrew)

A text for repro is 暑い (which is Japanese for "hot"). 