perf(ads): preconnect + preload Slise embed so banners render as the page loads

index.html

@@ -4,6 +4,12 @@
     <meta charset="UTF-8" />
     <link rel="icon" href="/favicon.ico" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <!-- Warm up the Slise ad origin and start fetching the embed script in
+         parallel with the app bundle, so banners can render as the page loads
+         instead of after the ad component mounts. -->
+    <link rel="preconnect" href="https://v1.slise.xyz" crossorigin />
+    <link rel="dns-prefetch" href="https://v1.slise.xyz" />
+    <link rel="preload" href="https://v1.slise.xyz/scripts/embed.js" as="script" />
     <title>Ping Dashboard - Cosmos Blockchain Explorer And Web Wallet</title>
     <meta
       name="description"

src/components/ad/AdBanner.vue

@@ -21,6 +21,8 @@ declare global {
   }
 }
 
+const SLISE_EMBED_SRC = 'https://v1.slise.xyz/scripts/embed.js';
+
 const props = defineProps({
   slot: {
     type: String,
@@ -81,22 +83,28 @@ onMounted(() => {
     observer.observe(containerRef.value);
   }
 
-  // Load script only once
-  if (!document.querySelector('script[src="https://v1.slise.xyz/scripts/embed.js"]')) {
+  // Queue this slot for Slise.
+  window.adsbyslise = window.adsbyslise || [];
+  window.adsbyslise.push({ slot: props.slot });
+
+  // Fill the slot as soon as Slise's embed script is ready. Waiting for the
+  // script's `load` event (instead of a one-shot check) means the very first
+  // banner fills the moment the script arrives, rather than only on Slise's
+  // internal 1s location poll.
+  const sync = () => window.adsbyslisesync?.();
+  const existing = document.querySelector(`script[src="${SLISE_EMBED_SRC}"]`);
+
+  if (window.adsbyslisesync) {
+    sync();
+  } else if (existing) {
+    existing.addEventListener('load', sync, { once: true });
+  } else {
     const script = document.createElement('script');
-    script.src = 'https://v1.slise.xyz/scripts/embed.js';
+    script.src = SLISE_EMBED_SRC;
     script.async = true;
+    script.addEventListener('load', sync, { once: true });
     document.head.appendChild(script);
   }
-
-  // Initialize ad queue
-  window.adsbyslise = window.adsbyslise || [];
-  window.adsbyslise.push({ slot: props.slot });
-
-  // Sync if available
-  if (typeof window.adsbyslisesync === 'function') {
-    window.adsbyslisesync();
-  }
 });
 
 onBeforeUnmount(() => {