fix: transparent PNG logos for Vantage and PolyGen (no background boxes)

Author: Reg (Ceradon AI)

assets/polygen-logo.png

@@ -138,7 +138,7 @@ <h1 class="text-4xl sm:text-5xl font-bold text-[color:var(--white)]">Passive thr
               </div>
             </div>
             <div class="card-glass p-8 space-y-4">
-              <img src="./assets/vantage-mark.webp" alt="Vantage &mdash; WiFi CSI through-wall sensing" class="w-full max-w-xs image-surface rounded" loading="lazy" width="1920" height="1080" />
+              <img src="./assets/vantage-logo.png" alt="Vantage &mdash; WiFi CSI through-wall sensing" class="w-full max-w-sm" loading="lazy" />
               <h2 class="text-xl font-semibold text-[color:var(--white)]">What works now</h2>
               <ul class="space-y-2 text-sm text-subtle">
                 <li class="flex gap-2"><span class="text-green-400">&#10003;</span> Presence detection via WiFi CSI</li>