feat(homepage): update section title to "The Arcade"

Replace "Available Now" section with "The Arcade" to better describe
the multiplayer room system. Updated subtitle to explain that users
can create or join rooms to play real-time games with friends over
the network.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/web/src/app/page.tsx

@@ -360,10 +360,11 @@ export default function HomePage() {
                     mb: '2',
                   })}
                 >
-                  Available Now
+                  The Arcade
                 </h2>
                 <p className={css({ color: 'gray.400', fontSize: 'md' })}>
-                  Foundation tutorials and reinforcement games ready to use
+                  Create or join multiplayer rooms to play real-time games with friends over the
+                  network
                 </p>
               </div>