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/chat/chat-header.tsx

@@ -0,0 +1,76 @@
+"use client";
+
+import { PanelLeftIcon } from "lucide-react";
+import Link from "next/link";
+import { memo } from "react";
+import { Button } from "@/components/ui/button";
+import { useSidebar } from "@/components/ui/sidebar";
+import { VercelIcon } from "./icons";
+import { VisibilitySelector, type VisibilityType } from "./visibility-selector";
+
+function PureChatHeader({
+  chatId,
+  selectedVisibilityType,
+  isReadonly,
+}: {
+  chatId: string;
+  selectedVisibilityType: VisibilityType;
+  isReadonly: boolean;
+}) {
+  const { state, toggleSidebar, isMobile } = useSidebar();
+
+  if (state === "collapsed" && !isMobile) {
+    return null;
+  }
+
+  return (
+    <header className="sticky top-0 flex h-14 items-center gap-2 bg-sidebar px-3">
+      <Button
+        className="md:hidden"
+        onClick={toggleSidebar}
+        size="icon-sm"
+        variant="ghost"
+      >
+        <PanelLeftIcon className="size-4" />
+      </Button>
+
+      <Link
+        className="flex size-8 items-center justify-center rounded-lg md:hidden"
+        href="https://vercel.com/templates/next.js/chatbot"
+        rel="noopener noreferrer"
+        target="_blank"
+      >
+        <VercelIcon size={14} />
+      </Link>
+
+      {!isReadonly && (
+        <VisibilitySelector
+          chatId={chatId}
+          selectedVisibilityType={selectedVisibilityType}
+        />
+      )}
+
+      <Button
+        asChild
+        className="hidden rounded-lg bg-foreground px-4 text-background hover:bg-foreground/90 md:ml-auto md:flex"
+      >
+        <Link
+          href="https://vercel.com/templates/next.js/chatbot"
+          rel="noopener noreferrer"
+          target="_blank"
+        >
+          <VercelIcon size={16} />
+          Deploy with Vercel
+        </Link>
+      </Button>
+    </header>
+  );
+}
+
+export const ChatHeader = memo(PureChatHeader, (prevProps, nextProps) => {
+  return (
+    prevProps.chatId === nextProps.chatId &&
+    prevProps.selectedVisibilityType === nextProps.selectedVisibilityType &&
+    prevProps.isReadonly === nextProps.isReadonly
+  );
+});