Rephrase ASCII requirement in system prompt: Generated content, not file encoding.

What variant of Codex are you using?

CLI

What feature would you like to see?

The system prompts in this repo instructs to prefer ASCII. My interpretation is that this is about what the agent produces, not about the file encoding. On Windows (not WSL), it seems to have the effect that files are read/written with ASCII/default encoding, causing garbled text (mojibake) if a file is already UTF-8 and contains non-ASCII characters (such as æøå).

The prompt should be updated to clarify that the ASCII preference is for generated content, and that all files should be read/written as UTF-8 unless otherwise specified, or something. (UTF-8 is, after all, compatible with ASCII for ASCII-only content.)

Additional information

_No response_