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/hoshiforge-studio.svg

@@ -0,0 +1,13 @@
+<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)"/>
+  <rect x="64" y="64" width="384" height="384" rx="96" fill="rgba(255,255,255,0.08)" stroke="rgba(255,255,255,0.2)" stroke-width="8"/>
+  <path d="M152 336L256 144L360 336H312L286 286H226L200 336H152ZM245 244H267L256 222L245 244Z" fill="#FFF8ED"/>
+  <circle cx="350" cy="166" r="28" fill="#FFD166"/>
+  <defs>
+    <linearGradient id="bg" x1="82" y1="56" x2="430" y2="448" gradientUnits="userSpaceOnUse">
+      <stop stop-color="#2A1F5E"/>
+      <stop offset="0.55" stop-color="#5D38B1"/>
+      <stop offset="1" stop-color="#F97362"/>
+    </linearGradient>
+  </defs>
+</svg>