Terminal tool breaks non-ASCII output on Windows (Opencode Desktop) #20843

Description

This only affects the desktop version of OpenCode; the TUI version appears to be unaffected.

Examples

Russian:

echo "Привет, мир!"

�ਢ��, ���!

Japanese:

echo "こんにちは世界"

???????

Chinese:

echo "你好，世界"

??,??

Korean:

echo "안녕하세요 세계"

????? ??

Arabic:

echo "مرحبا بالعالم"

????? ???????

Emoji:

echo "Hello 👋"

Hello ??

But if UTF-8 is set before the command, output becomes correct:

[Console]::InputEncoding = [System.Text.UTF8Encoding]::new()
[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new()
$OutputEncoding = [System.Text.UTF8Encoding]::new()
chcp 65001 > $null
echo "Привет, мир!"

Привет, мир!

This can't be fixed by PowerShell profile settings becouse Opencode Desktop start powershell process with -NoProfile

Plugins

No

OpenCode version

Desktop v1.3.13 Windows 11 (installed with scoop)

Steps to reproduce

Launch opencode desktop app then say to agent something like "call terminal tool and use echo to print hello world in Russian/Japanese/Chinese/etc"

Screenshot and/or share link

No response

Operating System

Microsoft Windows [Version 10.0.22631.5472]

Terminal

Opencode Desktop