leaderboard: tighten mobile gallery box to a single scroll

Increase the mobile chrome reserve so the capped box fits the phone
viewport (kills the residual outer page scroll on top of the box's own
scroll). GT row stays pinned; shows the GT + a couple of models with the
rest reachable by scrolling the box.

Co-authored-by: Cursor <cursoragent@cursor.com>

gallery.py

@@ -700,8 +700,8 @@ function sizeGalleryBox() {
     // internally on mobile so the GT row + sample headers stay pinned and each
     // model's renders sit under the matching GT render (same as desktop).
     const narrow = (window.innerWidth || 1000) < 760;
-    const reserve = narrow ? 360 : CHROME_RESERVE;
-    const maxH = narrow ? 560 : 1200;
+    const reserve = narrow ? 410 : CHROME_RESERVE;
+    const maxH = narrow ? 520 : 1200;
     const minH = narrow ? 280 : 320;
     const h = Math.max(minH, Math.min(maxH, Math.round(avail - reserve)));
     document.documentElement.style.setProperty('--gallery-max', h + 'px');