perf: make admin navigation responsive

public/admin/assets/js/app.js

@@ -148,7 +148,7 @@ async function loadGlobalStats() {
   if (!bar) return;
 
   try {
-    const data = await api("/admin/api/stats");
+    const data = await api("/admin/api/stats/summary");
     const t = document.getElementById("s-total");
     if (t) t.textContent = data.total.toLocaleString();
     const c = document.getElementById("s-content");
@@ -161,6 +161,49 @@ async function loadGlobalStats() {
 }
 
 
+function installLoadingStates() {
+  document.querySelectorAll("tbody:empty").forEach(tbody => {
+    const columns = Math.max(1, tbody.closest("table")?.querySelectorAll("thead th").length || 5);
+    tbody.setAttribute("aria-busy", "true");
+    tbody.innerHTML = `<tr class="skeleton-row"><td colspan="${columns}"><span></span><span></span><span></span><span></span></td></tr>`;
+    const observer = new MutationObserver(() => {
+      if (!tbody.querySelector(".skeleton-row")) {
+        tbody.removeAttribute("aria-busy");
+        observer.disconnect();
+      }
+    });
+    observer.observe(tbody, { childList: true });
+  });
+  ["intel-signals-grid", "sourceTable", "statusTable"].forEach(id => {
+    const node = document.getElementById(id);
+    if (node && !node.children.length) node.classList.add("content-loading");
+  });
+}
+
+
+function installNavigationPrefetch() {
+  const seen = new Set();
+  const prefetch = link => {
+    const href = link?.href;
+    if (!href || seen.has(href) || link.origin !== location.origin) return;
+    seen.add(href);
+    const hint = document.createElement("link");
+    hint.rel = "prefetch";
+    hint.href = href;
+    hint.as = "document";
+    document.head.appendChild(hint);
+  };
+  document.querySelectorAll(".tabs a, .subnav a").forEach(link => {
+    link.addEventListener("pointerenter", () => prefetch(link), { once: true });
+    link.addEventListener("focus", () => prefetch(link), { once: true });
+    link.addEventListener("click", () => document.documentElement.classList.add("navigating"));
+  });
+  const warm = () => document.querySelectorAll(".tabs a, .subnav a").forEach(prefetch);
+  if ("requestIdleCallback" in window) requestIdleCallback(warm, { timeout: 2500 });
+  else setTimeout(warm, 1200);
+}
+
+
 // common overlay close-on-backdrop wiring
 function wireOverlays() {
   document.querySelectorAll(".overlay").forEach(ov => {
@@ -173,6 +216,10 @@ function wireOverlays() {
 
 document.addEventListener("DOMContentLoaded", () => {
   installChrome();
+  installLoadingStates();
+  installNavigationPrefetch();
   wireOverlays();
-  loadGlobalStats();
+  const loadStats = () => loadGlobalStats();
+  if ("requestIdleCallback" in window) requestIdleCallback(loadStats, { timeout: 1800 });
+  else setTimeout(loadStats, 500);
 });

public/admin/assets/js/intel-signals.js

@@ -13,6 +13,7 @@ const signalsById = new Map();
 function renderSignals(data) {
   const grid  = document.getElementById("intel-signals-grid");
   const empty = document.getElementById("intel-signals-empty");
+  grid.classList.remove("content-loading");
 
   if (!data || data.length === 0) {
     grid.innerHTML = "";

public/admin/assets/js/stats.js

@@ -4,6 +4,9 @@
 async function loadStatsPage() {
   const data = await api("/admin/api/stats");
 
+  document.getElementById("sourceTable").classList.remove("content-loading");
+  document.getElementById("statusTable").classList.remove("content-loading");
+
   document.getElementById("sourceTable").innerHTML = data.bySource
     .map(r => `<tr><td>${escapeHtml(r.source)}</td><td style="text-align:right; padding-left:24px">${r.n.toLocaleString()}</td></tr>`).join("");