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/page.tsx

@@ -1,4 +1,5 @@
 import Link from "next/link";
+import { ContentCard, EmptyState } from "@/components/public/ui";
 import { excerpt } from "@/lib/format";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
@@ -20,13 +21,16 @@ export default async function HomePage() {
   }
 
   return (
-    <main>
-      <section className="hero">
-        <h1 style={{ fontSize: 36, marginTop: 0 }}>Welcome to {hotelName}</h1>
-        <p className="muted" style={{ fontSize: 16 }}>
-          Your retro hotel, now powered by Next.js. Hang out, collect furni, and meet friends.
+    <main style={{ display: "grid", gap: "1.5rem" }}>
+      <ContentCard
+        icon="🏨"
+        title={`Welcome to ${hotelName}`}
+        subtitle="Your retro hotel, now powered by Next.js"
+      >
+        <p className="muted" style={{ margin: "0 0 0.9rem" }}>
+          Hang out, collect furni, and meet friends.
         </p>
-        <div style={{ display: "flex", gap: "0.6rem", marginTop: "0.5rem" }}>
+        <div style={{ display: "flex", gap: "0.6rem", flexWrap: "wrap" }}>
           <Link className="btn btn-primary" href="/client">
             Enter hotel
           </Link>
@@ -34,28 +38,47 @@ export default async function HomePage() {
             Latest news
           </Link>
         </div>
-      </section>
+      </ContentCard>
 
-      <h2>Latest news</h2>
-      {articles.length === 0 ? (
-        <p className="muted">No articles yet.</p>
-      ) : (
-        <div className="grid cols-2">
-          {articles.map((a) => (
-            <article key={a.slug} className="card hover article">
-              {a.image ? <img className="article-img" src={a.image} alt="" /> : <div className="article-img" />}
-              <div className="body">
-                <h3 style={{ margin: "0 0 0.3rem" }}>
-                  <Link href={`/news/${a.slug}`}>{a.title}</Link>
-                </h3>
-                <p className="muted" style={{ margin: 0 }}>
-                  {excerpt(a.shortStory, 120)}
-                </p>
-              </div>
-            </article>
-          ))}
-        </div>
-      )}
+      <ContentCard
+        icon="📰"
+        title="Latest news"
+        subtitle="Fresh from the hotel"
+        action={
+          <Link className="btn btn-outline" href="/news">
+            All news →
+          </Link>
+        }
+      >
+        {articles.length === 0 ? (
+          <EmptyState icon="📰">No articles yet.</EmptyState>
+        ) : (
+          <div className="card-grid sm-2 lg-4">
+            {articles.map((a) => (
+              <article
+                key={a.slug}
+                className="card hover"
+                style={{ padding: 0, overflow: "hidden" }}
+              >
+                {a.image ? (
+                  // biome-ignore lint/performance/noImgElement: external article image
+                  <img className="article-img" src={a.image} alt="" />
+                ) : (
+                  <div className="article-img" />
+                )}
+                <div style={{ padding: "0.85rem" }}>
+                  <h3 style={{ margin: "0 0 0.3rem", fontSize: "1rem" }}>
+                    <Link href={`/news/${a.slug}`}>{a.title}</Link>
+                  </h3>
+                  <p className="muted" style={{ margin: 0 }}>
+                    {excerpt(a.shortStory, 110)}
+                  </p>
+                </div>
+              </article>
+            ))}
+          </div>
+        )}
+      </ContentCard>
     </main>
   );
 }