Cyrillic characters are not displayed correctly in diff view

[uqe]

When editing a file that contains Cyrillic text (e.g., Привет, это кириллица), the diff view shows garbled or incorrectly encoded characters instead of the original Unicode string.

Versions:

• opencode: 0.1.130
• tmux: 3.5a
• macOS: 15.5
• Alacritty: 0.15.1

Steps to Reproduce:

1. Create a file with a line containing Cyrillic text: Привет, это кириллица
2. Edit the file and replace the Cyrillic line with: Hey, now this is Latin letters
3. Check the diff view.

Expected Behavior:
The diff should show the original line in proper Cyrillic characters.

Screenshot: