Refresh ARServer landing sitemap

Author: masarray

docs/sitemap.xml

@@ -2,7 +2,7 @@
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
   <url>
     <loc>https://masarray.github.io/arserver/</loc>
-    <lastmod>2026-06-05</lastmod>
+    <lastmod>2026-06-18</lastmod>
     <changefreq>weekly</changefreq>
     <priority>1.0</priority>
   </url>