feat: add sitemap page with card grid layout

js/sitemap.js

@@ -0,0 +1,43 @@
+function renderSitemap() {
+  if (typeof sites === "undefined") return;
+
+  var projectContainer = document.getElementById("project-cards");
+  if (projectContainer) {
+    projectContainer.innerHTML = sites.projects.map(function (s) {
+      var subLink = "";
+      if (s.subLinks && s.subLinks.length > 0) {
+        subLink = s.subLinks.map(function (sl) {
+          return '<a href="' + sl.url + '" class="site-card-sublink" target="_blank" rel="noopener">' + sl.label + ' ↗</a>';
+        }).join("");
+      }
+
+      return (
+        '<div class="site-card-wrapper">' +
+          '<a href="' + s.url + '" class="site-card" target="_blank" rel="noopener">' +
+            '<div class="site-card-icon">' + s.icon + "</div>" +
+            '<div class="site-card-name">' + s.name + "</div>" +
+            '<div class="site-card-desc">' + s.description + "</div>" +
+          "</a>" +
+          subLink +
+        "</div>"
+      );
+    }).join("");
+  }
+
+  var infraContainer = document.getElementById("infra-cards");
+  if (infraContainer) {
+    infraContainer.innerHTML = sites.infra.map(function (s) {
+      return (
+        '<a href="' + s.url + '" class="infra-card" target="_blank" rel="noopener">' +
+          '<div class="infra-card-icon">' + s.icon + "</div>" +
+          '<div class="infra-card-name">' + s.name + "</div>" +
+          '<div class="infra-card-desc">' + s.description + "</div>" +
+        "</a>"
+      );
+    }).join("");
+  }
+}
+
+document.addEventListener("DOMContentLoaded", function () {
+  renderSitemap();
+});