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

app/(auth)/auth.config.ts

@@ -0,0 +1,14 @@
+import type { NextAuthConfig } from "next-auth";
+
+const base = process.env.NEXT_PUBLIC_BASE_PATH ?? "";
+
+export const authConfig = {
+  basePath: "/api/auth",
+  trustHost: true,
+  pages: {
+    signIn: `${base}/login`,
+    newUser: `${base}/`,
+  },
+  providers: [],
+  callbacks: {},
+} satisfies NextAuthConfig;