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

components/ui/spinner.tsx

@@ -0,0 +1,10 @@
+import { cn } from "@/lib/utils"
+import { Loader2Icon } from "lucide-react"
+
+function Spinner({ className, ...props }: React.ComponentProps<"svg">) {
+  return (
+    <Loader2Icon role="status" aria-label="Loading" className={cn("size-4 animate-spin", className)} {...props} />
+  )
+}
+
+export { Spinner }