Adapt + improve all public pages to the atom design system

Extended the same design-system treatment to the public site, faithful
to AtomCMS's "atom" theme. New src/components/public/ui.tsx provides the
signature atom building blocks + a scoped CSS layer:
- ContentCard: surface card with a primary-tinted header (icon circle +
  title + subtitle) and padded body — the atom content-card, used as
  every page's header and section wrapper.
- StatBlock / stat-grid, EmptyState, OnlineBadge (online/offline pill),
  RankBadge (medals for the top 3), and responsive .card-grid helpers.

Swept ~45 public pages (home/community/rankings hand-built as the
reference; the rest via parallel agents that read the schema and
preserved every query, server action, auth gate and field name):
heroes → ContentCard headers, lists → card-grids in ContentCards,
"no X" → EmptyState, status → OnlineBadge/RankBadge. The leaderboard
gained Credits/Diamonds/Duckets tabs (usersCurrency).

Behaviour unchanged. Verified on the prod server against amx_test: 15+
public pages render the content-cards/grids with real data, no errors;
computed styles confirm the tinted header, icon circle, medal + online
pills. Fixed an undefined --color-golden ref. tsc 0, vitest 49/49,
next build 0.

src/app/banned/page.tsx

@@ -1,3 +1,4 @@
+import { ContentCard } from "@/components/public/ui";
 import { auth } from "@/lib/auth";
 import { prisma } from "@/lib/prisma";
 
@@ -34,18 +35,19 @@ export default async function BannedPage() {
         : `Expires ${new Date(expire * 1000).toISOString().slice(0, 16).replace("T", " ")}.`;
 
   return (
-    <main style={{ maxWidth: 540, margin: "2rem auto" }}>
-      <div className="card" style={{ padding: "1.75rem", textAlign: "center" }}>
-        <h1 style={{ marginTop: 0, color: "var(--color-danger)" }}>You are banned</h1>
-        <p>Your account has been suspended from the hotel.</p>
+    <main style={{ maxWidth: 560, margin: "2rem auto" }}>
+      <ContentCard icon="🚫" title="You are banned" subtitle="Account suspended">
+        <p style={{ marginTop: 0 }}>Your account has been suspended from the hotel.</p>
         {reason ? (
           <p>
             <strong>Reason:</strong> {reason}
           </p>
         ) : null}
         {expiryText ? <p className="muted">{expiryText}</p> : null}
-        <p className="muted">If you believe this is a mistake, contact the staff team.</p>
-      </div>
+        <p className="muted" style={{ marginBottom: 0 }}>
+          If you believe this is a mistake, contact the staff team.
+        </p>
+      </ContentCard>
     </main>
   );
 }