Update AI SDK Example (#2271)

examples/vercel-ai-sdk-chat-app/src/constants/messages.ts

@@ -0,0 +1,31 @@
+import { Message } from "@/types";
+
+export const WELCOME_MESSAGE: Message = {
+  id: "1",
+  content: "👋 Hi there! I'm your personal assistant. How can I help you today? 😊",
+  sender: "assistant",
+  timestamp: new Date().toLocaleTimeString(),
+};
+
+export const INVALID_CONFIG_MESSAGE: Message = {
+  id: "2",
+  content: "Invalid configuration. Please check your API keys, and add a user and try again.",
+  sender: "assistant",
+  timestamp: new Date().toLocaleTimeString(),
+};
+
+export const ERROR_MESSAGE: Message = {
+  id: "3",
+  content: "Something went wrong. Please try again.",
+  sender: "assistant",
+  timestamp: new Date().toLocaleTimeString(),
+};
+
+export const AI_MODELS = {
+  openai: "gpt-4o",
+  anthropic: "claude-3-haiku-20240307",
+  cohere: "command-r-plus",
+  groq: "gemma2-9b-it",
+} as const;
+
+export type Provider = keyof typeof AI_MODELS;