Extract season overview/workflow cards and add sponsor seed data

Splits AdminSeasonsView into AdminSeasonOverviewCard and AdminSeasonWorkflowCard
for cleaner separation of concerns. Adds SeedSponsorsBootstrapper with demo
sponsor SVG assets and extends SeedCatalog with sponsor seed entries.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/public/demo/sponsors/prismloop-audio.svg

@@ -0,0 +1,15 @@
+<svg width="512" height="512" viewBox="0 0 512 512" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <rect width="512" height="512" rx="124" fill="url(#bg)"/>
+  <circle cx="256" cy="256" r="118" fill="rgba(255,255,255,0.1)" stroke="rgba(255,255,255,0.22)" stroke-width="12"/>
+  <circle cx="256" cy="256" r="42" fill="#FFF7ED"/>
+  <path d="M126 286C152 250 170 228 182 220C194 212 204 224 214 240C224 256 232 274 244 278C256 282 266 274 278 252C290 230 302 214 316 216C330 218 346 238 386 286" stroke="#FDBA74" stroke-width="22" stroke-linecap="round" stroke-linejoin="round"/>
+  <path d="M166 174V338" stroke="#FFF7ED" stroke-width="14" stroke-linecap="round"/>
+  <path d="M346 174V338" stroke="#FFF7ED" stroke-width="14" stroke-linecap="round"/>
+  <defs>
+    <linearGradient id="bg" x1="78" y1="70" x2="434" y2="442" gradientUnits="userSpaceOnUse">
+      <stop stop-color="#083344"/>
+      <stop offset="0.5" stop-color="#0F766E"/>
+      <stop offset="1" stop-color="#14B8A6"/>
+    </linearGradient>
+  </defs>
+</svg>