feat : add stygian guide

components/admin/admin-header.tsx

@@ -12,6 +12,7 @@ import {
   LogOutIcon,
   PlusIcon,
   UserPlusIcon,
+  SwordsIcon,
 } from "lucide-react";
 
 import { Button } from "@/components/ui/button";
@@ -32,6 +33,15 @@ export function AdminHeader() {
           <span className="hidden sm:inline">ไกด์เกนชินไม่ใช่เกมมือถือ</span>
         </Link>
         <nav aria-label="Admin navigation" className="flex items-center gap-1">
+          <Button
+            variant={pathname === "/admin/stygian" ? "secondary" : "ghost"}
+            size="sm"
+            nativeButton={false}
+            render={<Link href="/admin/stygian" />}
+          >
+            <SwordsIcon data-icon="inline-start" />
+            <span className="hidden sm:inline">Stygian</span>
+          </Button>
           <Button
             variant={pathname === "/admin/activity" ? "secondary" : "ghost"}
             size="sm"