Initial commit: EGBE chatbot template

Stripped from vercel/chatbot (Apache 2.0):
- Dropped @vercel/* packages and AI Gateway
- Removed artifacts feature (code/text/sheet/image side panel)
- Switched AI provider to @ai-sdk/openai-compatible -> EGBE LiteLLM
- Replaced Vercel Blob upload with data URLs
- Dropped Redis resumable streams and rate limiter (in-memory now)
- Added Dockerfile (Next.js standalone) + entrypoint that runs migrations
- Wired DATABASE_URL, EGBE_AI_API_URL/KEY, NEXT_PUBLIC_BASE_URL for app-deploy.sh

lib/types.ts

@@ -0,0 +1,32 @@
+import type { InferUITool, UIMessage } from "ai";
+import { z } from "zod";
+import type { getWeather } from "./ai/tools/get-weather";
+
+export const messageMetadataSchema = z.object({
+  createdAt: z.string(),
+});
+
+export type MessageMetadata = z.infer<typeof messageMetadataSchema>;
+
+type weatherTool = InferUITool<typeof getWeather>;
+
+export type ChatTools = {
+  getWeather: weatherTool;
+};
+
+export type CustomUIDataTypes = {
+  appendMessage: string;
+  "chat-title": string;
+};
+
+export type ChatMessage = UIMessage<
+  MessageMetadata,
+  CustomUIDataTypes,
+  ChatTools
+>;
+
+export type Attachment = {
+  name: string;
+  url: string;
+  contentType: string;
+};