Add robots.txt and sitemap.xml for search engine indexing

www/sitemap.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset
+        xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+
+    <url>
+        <loc>https://nx9.in/</loc>
+        <lastmod>2026-07-05</lastmod>
+        <changefreq>weekly</changefreq>
+        <priority>1.0</priority>
+    </url>
+
+    <url>
+        <loc>https://nx9.in/case-study.html</loc>
+        <lastmod>2026-07-05</lastmod>
+        <changefreq>monthly</changefreq>
+        <priority>0.9</priority>
+    </url>
+
+</urlset>