- Add normalizeInputForCodexAPI function to convert AI SDK multi-part
content format to simplified format expected by ChatGPT Codex API
- AI SDK sends: {"content": [{"type": "input_text", "text": "..."}]}
- Codex API expects: {"content": "..."}
- Only applies to OAuth accounts (ChatGPT internal API)
- API Key accounts remain unchanged (OpenAI Platform API supports both)