about/show-coverage: redesign with sidebar (300x600 + rotating 300x250s)

Switch the bare single-column layouts on these pages to a two-column
grid that pulls in <SidebarAdStack /> on the right (pinned 300x600 +
every 300x250 rotated). Header keeps the leaderboard above. The
in-content 728x90 banners added earlier are removed since the sidebar
now carries the ad load (avoids stacking two of the same unit on the
page).

Pages updated:
  - /show-coverage/[slug]   event detail
  - /about
  - /about/contact
  - /about/team
  - /about/advertise (also gets a real-banner grid in "Available units":
    the actual 728x90, 300x600, and 300x250 sample creatives are
    rendered next to each unit's description, so advertisers see what
    the inventory looks like in production rather than just a label).

The /about pages also got a small refresh: serif H1 + accent-blue
"Broadcast Beat" eyebrow line + bordered content blocks, bringing the
look closer to the cinematic homepage.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/show-coverage/[slug]/page.tsx

@@ -4,6 +4,7 @@ import { createClient } from "@supabase/supabase-js";
 import Header from "@/components/Header";
 import Footer from "@/components/Footer";
 import AdImage from "@/components/AdImage";
+import SidebarAdStack from "@/components/SidebarAdStack";
 import { ADS_728X90, shuffle } from "@/lib/ads";
 
 export const dynamic = "force-dynamic";
@@ -162,11 +163,13 @@ export default async function EventCoveragePage({
   return (
     <div className="min-h-screen bg-background">
       <Header />
-      <main className="mx-auto max-w-5xl px-6 py-10 text-[#e5e7eb]">
+      <div className="mx-auto max-w-6xl px-6 py-10 text-[#e5e7eb]">
         <script
           type="application/ld+json"
           dangerouslySetInnerHTML={{ __html: JSON.stringify(eventJsonLd) }}
         />
+        <div className="lg:grid lg:grid-cols-[1fr,300px] lg:gap-8">
+        <main>
         <Link href="/show-coverage" className="text-sm text-[var(--color-text-info,#60a5fa)] hover:underline">
           ← All events
         </Link>
@@ -245,7 +248,16 @@ export default async function EventCoveragePage({
             </ul>
           )}
         </section>
-      </main>
+        </main>
+
+        {/* Sidebar: 300x600 + rotating 300x250s */}
+        <aside className="mt-10 lg:mt-0" aria-label="Advertisements">
+          <div className="lg:sticky lg:top-24">
+            <SidebarAdStack />
+          </div>
+        </aside>
+        </div>
+      </div>
       <Footer />
     </div>
   );