feat: implement discord-based admin authentication for the form management page and add skill documentation

app/admin/form/page.tsx

@@ -14,10 +14,22 @@ import { Badge } from "@/components/ui/badge";
 import { Plus, Trash2 } from "lucide-react";
 import { redirect } from "next/navigation";
 import { deleteForm } from "@/app/actions/form";
+import { getServerSession } from "next-auth";
+import { authOptions } from "@/app/api/auth/[...nextauth]/route";
 
 export const dynamic = "force-dynamic";
 
 export default async function AdminFormsPage() {
+  const session = await getServerSession(authOptions);
+  const adminIds = (process.env.ADMIN_DISCORD_IDS ?? "")
+    .split(",")
+    .map((s) => s.trim())
+    .filter(Boolean);
+  const discordId = (session?.user as any)?.discordId;
+
+  if (!discordId || !adminIds.includes(discordId)) {
+    redirect("/");
+  }
   const formsList = await db.query.forms.findMany({
     orderBy: (f, { desc }) => [desc(f.createdAt)],
   });