Japanese text output is garbled due to encoding issues

What version of Codex is running?

0.42.0

Which model were you using?

gpt-5-codex

What platform is your computer?

Microsoft Windows NT 10.0.26100.0 x64

What steps can reproduce the bug?

Description

When generating code or text containing Japanese characters, the output is garbled (mojibake).
It looks like an encoding issue (possibly UTF-8 vs Shift-JIS or similar).

Steps to Reproduce

1. Generate text/code that includes Japanese characters using Codex.
2. Observe that the output contains broken characters like ã^A“ã‚“ã^A«ã^A¡ã^A¯.

Expected Behavior

Japanese characters should be displayed correctly (e.g., こんにちは).

Actual Behavior

Japanese characters are displayed as mojibake (garbled text).

Additional Context

It seems to be an encoding mismatch in the text stream. UTF-8 should be enforced for Japanese output.

What is the expected behavior?

_No response_

What do you see instead?

_No response_

Additional information

_No response_