Replace per-card product images with shared banner + dropdown selector

- Removed individual Fine.webp / Lacuoer.jpg from brand cards
- Added shared banner image (asset/banner/1.png) spanning both cards
- Added dropdown selector (Banner 1–9) to switch the displayed image
- Made card backgrounds semi-transparent so the banner shows through
- Added hover zoom effect on the shared banner
- Preserved all brand links, overlays, and content layouts

script.js

@@ -34,4 +34,18 @@
     },
     { passive: true }
   );
+
+  /* ── Banner image selector ──────────────────────────────── */
+  var bannerPicker = document.getElementById("banner-picker");
+  var bannerImg = document.getElementById("brands-banner");
+  if (bannerPicker && bannerImg) {
+    bannerPicker.addEventListener("change", function () {
+      var val = this.value;
+      bannerImg.style.opacity = "0";
+      setTimeout(function () {
+        bannerImg.src = "asset/banner/" + val + ".png";
+        bannerImg.style.opacity = "1";
+      }, 200);
+    });
+  }
 })();