need to set baseUrl

https://github.com/tinykit-studio/tinykit/blob/2bc27ba361807e1b5124c668c03d3c4812f46a00/src/lib/ai/sdk-agent.ts#L278

```js
		case 'openai': {
			const openai = createOpenAI({
				apiKey: config.apiKey,
				baseURL: config.baseUrl,
			})
			return openai.chat(config.model)
		}
```

also I'm using vLLM and it only supports the old `chat` API and not the new `response` API