Make hero the full landing page; move quick links into hero editor

Remove the two-card destination row and the below-hero quick-links nav
from the portal so the hero fills the viewport with nothing rendered
after it. The 5 quick links (News, Screenshots, Five on Friday,
Monthly Newsletter, About) move into the hero editor as a third
buttons element in defaultLayout(), reusing the existing buttons
element type so they stay fully editable with no schema changes.

Also drop overflow:hidden on the hero section: on mobile, 100vh can
compute smaller than window.innerHeight, and with overflow hidden the
wrapped quick-links text was getting clipped at the bottom edge.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

client/src/lib/heroLayout.js

@@ -84,6 +84,25 @@ export function defaultLayout(teaser) {
           ],
         },
       },
+      {
+        id: 'default-quick-links',
+        type: 'buttons',
+        x: 50,
+        y: 85,
+        z: 3,
+        anchor: 'center',
+        props: {
+          align: 'center',
+          gap: 10,
+          items: [
+            { label: 'News', to: '/site/news', variant: 'ghost' },
+            { label: 'Screenshots', to: '/site/screenshots', variant: 'ghost' },
+            { label: 'Five on Friday', to: '/site/five-on-friday', variant: 'ghost' },
+            { label: 'Monthly Newsletter', to: '/site/newsletter', variant: 'ghost' },
+            { label: 'About', to: '/site/about', variant: 'ghost' },
+          ],
+        },
+      },
     ],
   }
 }