perf: optimize polling, stats cache, and frontend chunk splitting

admin-frontend/src/pages/ReportPage.vue

@@ -405,18 +405,51 @@ async function refreshAll(options = {}) {
   }
 }
 
+const REPORT_POLL_ACTIVE_MS = 5000
+const REPORT_POLL_HIDDEN_MS = 20000
+
 let refreshTimer = null
 
+function isPageHidden() {
+  if (typeof document === 'undefined') return false
+  return document.visibilityState === 'hidden'
+}
+
+function currentRefreshDelay() {
+  return isPageHidden() ? REPORT_POLL_HIDDEN_MS : REPORT_POLL_ACTIVE_MS
+}
+
+function stopRefreshLoop() {
+  if (!refreshTimer) return
+  clearTimeout(refreshTimer)
+  refreshTimer = null
+}
+
+function scheduleRefreshLoop() {
+  stopRefreshLoop()
+  refreshTimer = window.setTimeout(async () => {
+    refreshTimer = null
+    await refreshAll({ showLoading: false }).catch(() => {})
+    scheduleRefreshLoop()
+  }, currentRefreshDelay())
+}
+
+function onVisibilityChange() {
+  scheduleRefreshLoop()
+}
+
 onMounted(() => {
   refreshAll({ showLoading: false })
-  refreshTimer = setInterval(() => refreshAll({ showLoading: false }), 5000)
+    .catch(() => {})
+    .finally(() => {
+      scheduleRefreshLoop()
+    })
+  window.addEventListener('visibilitychange', onVisibilityChange)
 })
 
 onUnmounted(() => {
-  if (refreshTimer) {
-    clearInterval(refreshTimer)
-    refreshTimer = null
-  }
+  stopRefreshLoop()
+  window.removeEventListener('visibilitychange', onVisibilityChange)
 })
 </script>