align: unify container width to max-w-container across all pages; fix banner edge alignment

The Featured-story card's right edge wasn't lining up with any of the
ad banners below or beside it on the homepage. Two root causes:

  1. Pages I redesigned (/about, /about/contact, /about/team,
     /about/advertise, /show-coverage/[slug]) used `max-w-6xl px-6`
     (1152px / 24px-pad). Every other page uses `max-w-container
     px-4` (1200px / 16px-pad). Pages didn't line up with the
     header leaderboard or with each other.

  2. ArticleFeed used a flexible 12-col grid where lg:col-span-4
     ends up ~280px wide (depending on container) — so the 300x250
     image inside the sidebar didn't extend to the column's right
     edge, leaving a visual gap relative to the full-width Featured
     card above.

Fix:
  - All redesigned pages now use `max-w-container mx-auto px-4`.
  - ArticleFeed switches to `lg:grid-cols-[1fr,300px]` so the sidebar
    column is *exactly* 300px wide. The 300x250 ads fill that column
    flush, so their right edge meets the container's right padding
    edge — same x-position as the Featured card's right edge above.

Also linkified the "Relevant Media Properties" copyright string in
Footer.tsx → opens https://www.relevantmediaproperties.com/ in a new
tab.

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

src/components/Footer.tsx

@@ -140,7 +140,15 @@ export default function Footer() {
           <div className="flex items-center gap-4 text-xs font-body text-[#555]">
             <Link href="/privacy" className="hover:text-[#3b82f6] transition-colors">Privacy Policy</Link>
             <Link href="/terms" className="hover:text-[#3b82f6] transition-colors">Terms of Service</Link>
-            <span>© 2026 Relevant Media Properties. All rights reserved.</span>
+            <span>
+              © 2026 <a
+                href="https://www.relevantmediaproperties.com/"
+                target="_blank"
+                rel="noopener noreferrer"
+                className="hover:text-[#3b82f6] transition-colors underline-offset-2 hover:underline">
+                Relevant Media Properties
+              </a>. All rights reserved.
+            </span>
           </div>
         </div>