Codex CLI 0.160.1 preserves Windows environment variables for remote MCP servers

Codex CLI 0.160.1 preserves Windows environment variables for remote stdio MCP servers. When custom remote environments are configured, SYSTEMROOT, TEMP, and TMP are retained.

The update also ensures Unix hosts retain the Windows executor startup environment, as outlined in the [GitHub release changelog](https://github.com/openai/codex/releases/tag/rust-v0.160.1).