Add Codex load balancing documentation and refine JSON handling logic

- Updated README and README_CN to include a guide for configuring multiple account load balancing with CLI Proxy API.
- Enhanced JSON handling in gemini translators by differentiating object and string outputs.
- Added commented debug logging for Gemini CLI response conversion.

README_CN.md

@@ -424,6 +424,28 @@ export ANTHROPIC_MODEL=qwen3-coder-plus
 export ANTHROPIC_SMALL_FAST_MODEL=qwen3-coder-flash
 ```
 
+## Codex 多账户负载均衡
+
+启动 CLI Proxy API 服务器, 修改 `~/.codex/config.toml` 和 `~/.codex/auth.json` 文件。
+
+config.toml:
+```toml
+model_provider = "cliproxyapi"
+model = "gpt-5" # 你可以使用任何我们支持的模型
+model_reasoning_effort = "high"
+
+[model_providers.cliproxyapi]
+name = "cliproxyapi"
+base_url = "http://127.0.0.1:8317/v1"
+wire_api = "responses"
+```
+
+auth.json:
+```json
+{
+  "OPENAI_API_KEY": "sk-dummy"
+}
+```
 
 ## 使用 Docker 运行