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/message-editor.tsx

@@ -0,0 +1,33 @@
+"use client";
+
+import type { UseChatHelpers } from "@ai-sdk/react";
+import { deleteTrailingMessages } from "@/app/(chat)/actions";
+import type { ChatMessage } from "@/lib/types";
+
+export async function submitEditedMessage({
+  message,
+  text,
+  setMessages,
+  regenerate,
+}: {
+  message: ChatMessage;
+  text: string;
+  setMessages: UseChatHelpers<ChatMessage>["setMessages"];
+  regenerate: UseChatHelpers<ChatMessage>["regenerate"];
+}) {
+  await deleteTrailingMessages({ id: message.id });
+
+  setMessages((messages) => {
+    const index = messages.findIndex((m) => m.id === message.id);
+    if (index === -1) {
+      return messages;
+    }
+
+    return [
+      ...messages.slice(0, index),
+      { ...message, parts: [{ type: "text" as const, text }] },
+    ];
+  });
+
+  regenerate();
+}