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/help/[category]/page.tsx

@@ -1,5 +1,6 @@
 import Link from "next/link";
 import { notFound } from "next/navigation";
+import { ContentCard } from "@/components/public/ui";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
 
@@ -93,16 +94,12 @@ export default async function HelpCategoryPage({
   const hasButton = Boolean(cat.buttonText && cat.buttonText.trim() !== "");
 
   return (
-    <main>
-      <p style={{ margin: "0 0 0.75rem" }}>
+    <main style={{ display: "grid", gap: "1.5rem" }}>
+      <p style={{ margin: 0 }}>
         <Link href="/help">← Help Center</Link>
       </p>
 
-      <div className="hero">
-        <h1 style={{ margin: 0 }}>{title}</h1>
-      </div>
-
-      <article className="card">
+      <ContentCard icon="❓" title={title} subtitle="Help Center topic">
         {imageSrc ? (
           // eslint-disable-next-line @next/next/no-img-element
           <img
@@ -120,6 +117,7 @@ export default async function HelpCategoryPage({
         {/* content is author-supplied HTML in AtomCMS (rendered raw with {!! !!}). */}
         <div
           style={{ lineHeight: 1.7 }}
+          // biome-ignore lint/security/noDangerouslySetInnerHtml: author-supplied help content, matches AtomCMS Blade
           dangerouslySetInnerHTML={{ __html: content }}
         />
 
@@ -137,12 +135,15 @@ export default async function HelpCategoryPage({
             </a>
           </div>
         ) : null}
-      </article>
+      </ContentCard>
 
       {siblings.length > 0 ? (
-        <section style={{ marginTop: "2rem" }}>
-          <h2>More help topics</h2>
-          <div className="grid cols-2">
+        <ContentCard
+          icon="🧭"
+          title="More help topics"
+          subtitle="Jump to another support topic"
+        >
+          <div className="card-grid sm-2 lg-3">
             {siblings.map((s) => (
               <Link
                 key={String(s.id)}
@@ -154,7 +155,7 @@ export default async function HelpCategoryPage({
               </Link>
             ))}
           </div>
-        </section>
+        </ContentCard>
       ) : null}
     </main>
   );