Add sitemap.xml, robots.txt, and Twitter Card tags for privacy page

Improves crawlability and social sharing for the privacy page.

Author: one-kash

privacy/index.html

@@ -16,6 +16,12 @@
     <meta property="og:description" content="KashCal Privacy Policy. We do not collect any data.">
     <meta property="og:image" content="https://kashcal.github.io/icon-192.png">
 
+    <!-- Twitter Card -->
+    <meta name="twitter:card" content="summary">
+    <meta name="twitter:title" content="Privacy Policy - KashCal">
+    <meta name="twitter:description" content="KashCal Privacy Policy. We do not collect any data.">
+    <meta name="twitter:image" content="https://kashcal.github.io/icon-192.png">
+
     <link rel="icon" type="image/png" href="/favicon.png">
     <link rel="icon" type="image/png" sizes="192x192" href="/icon-192.png">
     <link rel="apple-touch-icon" href="/icon-192.png">

robots.txt

@@ -0,0 +1,4 @@
+User-agent: *
+Allow: /
+
+Sitemap: https://kashcal.github.io/sitemap.xml

sitemap.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+  <url>
+    <loc>https://kashcal.github.io/</loc>
+    <lastmod>2026-03-24</lastmod>
+  </url>
+  <url>
+    <loc>https://kashcal.github.io/privacy/</loc>
+    <lastmod>2026-03-24</lastmod>
+  </url>
+</urlset>