Stage 1: Course/Module/Lesson CRUD admin UI with TipTap editor

src/app/admin/layout.tsx

@@ -0,0 +1,30 @@
+import { headers } from "next/headers";
+import { auth } from "@/lib/auth";
+import { redirect } from "next/navigation";
+import { AdminNav } from "@/components/admin/admin-nav";
+import { LogoutButton } from "@/components/layout/logout-button";
+
+export default async function AdminLayout({ children }: { children: React.ReactNode }) {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session) redirect("/login");
+  if (session.user.role !== "admin") redirect("/dashboard");
+
+  return (
+    <div className="min-h-screen flex bg-slate-50">
+      <aside className="w-56 bg-slate-900 text-white flex flex-col shrink-0 fixed h-full z-10">
+        <div className="px-5 py-5 border-b border-slate-800">
+          <p className="font-bold text-amber-400 text-base">Second Brain</p>
+          <p className="text-xs text-slate-400 mt-0.5">Админ-панель</p>
+        </div>
+        <nav className="flex-1 p-3 space-y-0.5 overflow-y-auto">
+          <AdminNav />
+        </nav>
+        <div className="p-4 border-t border-slate-800">
+          <p className="text-xs text-slate-400 mb-3 truncate">{session.user.name}</p>
+          <LogoutButton />
+        </div>
+      </aside>
+      <div className="ml-56 flex-1 min-h-screen">{children}</div>
+    </div>
+  );
+}