remove ai plugin integration

app/api/chat/route.ts

@@ -1,27 +0,0 @@
-import { NextRequest } from "next/server";
-import { CLOUD_BASE, FRONTEND_API_KEY } from "@/lib/cloud";
-
-// Proxy the editor's AI chat requests to Frontend Cloud, injecting the API key
-// server-side so it is never exposed to the client. The cloud response is
-// streamed straight back to the caller.
-export async function POST(req: NextRequest) {
-  const upstream = await fetch(`${CLOUD_BASE}/api/chat`, {
-    method: "POST",
-    headers: {
-      "content-type": req.headers.get("content-type") ?? "application/json",
-      "x-api-key": FRONTEND_API_KEY,
-    },
-    body: req.body,
-    // Required by undici when forwarding a streaming request body.
-    // @ts-expect-error - duplex is valid but missing from the lib types.
-    duplex: "half",
-  });
-
-  return new Response(upstream.body, {
-    status: upstream.status,
-    headers: {
-      "content-type":
-        upstream.headers.get("content-type") ?? "application/octet-stream",
-    },
-  });
-}