fix(chess): ad banner takes full top void, hidden when no ad

Ad area now flex:1 (absorbs all dead space above the board).
Hidden by default — only shown when an active campaign is loaded.
Game UI pushed further down for thumb reach.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/js/modules/chess/scenes/game.js

@@ -98,14 +98,10 @@ export function mountGame(el, params) {
 
   el.innerHTML = `
     <div class="chess-layout" style="display:flex;flex-direction:column;height:100%;background:#1a1a2e;">
-      <!-- Ad Banner (top dead space) -->
-      <div id="ad-banner-top" style="flex:0 0 auto;min-height:50px;display:flex;align-items:center;justify-content:center;padding:6px 12px;background:#0a0a1a;cursor:pointer;" onclick="window.__adClick && window.__adClick()">
-        <div id="ad-content" style="width:100%;max-width:400px;height:50px;border-radius:8px;background:linear-gradient(135deg,#1e1e3a,#2a2a5a);display:flex;align-items:center;justify-content:center;overflow:hidden;border:1px solid rgba(255,255,255,0.05);">
-          <span style="font-size:11px;color:#475569;">إعلان</span>
-        </div>
+      <!-- Ad Banner — takes all top void space, hidden if no ad -->
+      <div id="ad-banner-top" style="flex:1;display:none;align-items:center;justify-content:center;padding:8px 12px;background:#0a0a1a;cursor:pointer;" onclick="window.__adClick && window.__adClick()">
+        <div id="ad-content" style="width:100%;height:100%;max-height:180px;border-radius:10px;overflow:hidden;display:flex;align-items:center;justify-content:center;"></div>
       </div>
-      <!-- Spacer — near center, slightly bottom-biased -->
-      <div style="flex:0.25;"></div>
       <!-- Opponent Bar (compact — keep minimal at top) -->
       <div class="chess-bar" style="display:flex;align-items:center;justify-content:space-between;padding:4px 12px;background:#0f0f1e;">
         <div style="display:flex;align-items:center;gap:8px;">
@@ -863,9 +859,11 @@ async function loadAdBanner(el) {
   try {
     const res = await net.post('ads.php', { action: 'get', slot: 'banner_top', game: 'chess' });
     if (!res || res.error || !res.image_url) return;
-    const banner = el.querySelector('#ad-content');
-    if (!banner) return;
-    banner.innerHTML = `<img src="${res.image_url}" style="width:100%;height:100%;object-fit:cover;border-radius:8px;">`;
+    const wrapper = el.querySelector('#ad-banner-top');
+    const content = el.querySelector('#ad-content');
+    if (!wrapper || !content) return;
+    content.innerHTML = `<img src="${res.image_url}" style="width:100%;height:100%;object-fit:cover;border-radius:10px;">`;
+    wrapper.style.display = 'flex';
     window.__adClick = () => {
       if (res.click_url) window.open(res.click_url, '_blank');
       net.post('ads.php', { action: 'impression', campaign_id: res.id }).catch(() => {});