feat(deck): use transparent SolLunar logo + emblem

Swap in the transparent-background logo (full lockup for the title hero,
cropped eclipse emblem for the top-bar mark + favicons). Drop the dark-card
framing since the logos now float on the deck canvas — hero keeps the
gold+blue glow and a drop-shadow; top-bar mark is object-contain. Favicons
regenerated with alpha.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/deck/Deck.vue

@@ -75,7 +75,7 @@ function onTouchEnd(e: TouchEvent) {
       class="pointer-events-none absolute inset-x-0 top-0 z-20 flex items-center justify-between px-6 py-5 text-fg-muted"
     >
       <span class="flex items-center gap-2">
-        <img :src="markUrl" alt="SolLunar" class="size-7 rounded-md object-cover ring-1 ring-line" />
+        <img :src="markUrl" alt="SolLunar" class="size-8 object-contain" />
         <span class="font-display text-sm font-semibold tracking-wide text-fg">SolLunar</span>
       </span>
       <div class="flex items-center gap-3">

src/deck/slides/TitleSlide.vue

@@ -28,7 +28,7 @@ import logoUrl from '@/deck/assets/logo.webp'
         <img
           :src="logoUrl"
           alt="SolLunar — Energy · Intelligence · Harmony"
-          class="w-56 rounded-3xl shadow-2xl ring-1 ring-line-2 sm:w-64 lg:w-72"
+          class="w-64 drop-shadow-2xl sm:w-72 lg:w-80"
         />
       </div>