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/cloudbeacon-hosting.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)"/>
+  <path d="M182 318C148 318 122 292 122 258C122 228 144 204 172 200C182 158 220 128 266 128C318 128 360 166 366 216C393 222 414 246 414 276C414 312 384 340 348 340H182V318Z" fill="#F8FAFC"/>
+  <rect x="176" y="228" width="160" height="28" rx="14" fill="#2563EB"/>
+  <rect x="176" y="270" width="130" height="24" rx="12" fill="#60A5FA"/>
+  <rect x="176" y="308" width="188" height="24" rx="12" fill="#93C5FD"/>
+  <path d="M342 162L362 188L394 192L372 214L378 246L350 232L322 246L328 214L306 192L338 188L342 162Z" fill="#FDE68A"/>
+  <defs>
+    <linearGradient id="bg" x1="78" y1="62" x2="432" y2="450" gradientUnits="userSpaceOnUse">
+      <stop stop-color="#111827"/>
+      <stop offset="0.48" stop-color="#1D4ED8"/>
+      <stop offset="1" stop-color="#38BDF8"/>
+    </linearGradient>
+  </defs>
+</svg>