fix(readme): update model references and image alt text

README.md

@@ -1,5 +1,5 @@
 <a href="https://chat.vercel.ai/">
-  <img alt="Next.js 14 and App Router-ready Chatbot." src="app/(chat)/opengraph-image.png">
+  <img alt="Chatbot" src="app/(chat)/opengraph-image.png">
   <h1 align="center">Chatbot</h1>
 </a>
 
@@ -24,7 +24,7 @@
 - [AI SDK](https://ai-sdk.dev/docs/introduction)
   - Unified API for generating text, structured objects, and tool calls with LLMs
   - Hooks for building dynamic chat and generative user interfaces
-  - Supports xAI (default), OpenAI, Fireworks, and other model providers
+  - Supports OpenAI, Anthropic, Google, xAI, and other model providers via AI Gateway
 - [shadcn/ui](https://ui.shadcn.com)
   - Styling with [Tailwind CSS](https://tailwindcss.com)
   - Component primitives from [Radix UI](https://radix-ui.com) for accessibility and flexibility
@@ -36,7 +36,7 @@
 
 ## Model Providers
 
-This template uses the [Vercel AI Gateway](https://vercel.com/docs/ai-gateway) to access multiple AI models through a unified interface. The default configuration includes [xAI](https://x.ai) models (`grok-2-vision-1212`, `grok-3-mini`) routed through the gateway.
+This template uses the [Vercel AI Gateway](https://vercel.com/docs/ai-gateway) to access multiple AI models through a unified interface. The default model is [OpenAI](https://openai.com) GPT-4.1 Mini, with support for Anthropic, Google, and xAI models.
 
 ### AI Gateway Authentication