Codex CLI 0.118.0 deprecated the OPENAI_BASE_URL env var. When users switch providers via /provider, the new base URL was set as an env var but ignored by the CLI. Now pass it as `-c openai_base_url=<url>` on each subprocess invocation so the correct endpoint is used immediately. Closes #554 Co-authored-by: Claude <noreply@anthropic.com>