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/components/public/ui.tsx

@@ -0,0 +1,103 @@
+import type { ReactNode } from "react";
+
+/**
+ * Public-site design system, faithful to AtomCMS's "atom" theme. The signature
+ * element is the content-card: a surface card with a primary-tinted header
+ * (icon circle + title + subtitle) and a padded body. These mirror the atom
+ * Blade components (content-card, stat blocks, empty states) so every public
+ * page shares one consistent, themeable look.
+ */
+
+export function ContentCard({
+  icon,
+  title,
+  subtitle,
+  action,
+  children,
+  className,
+  padded = true,
+}: {
+  icon?: string;
+  title?: ReactNode;
+  subtitle?: ReactNode;
+  action?: ReactNode;
+  children?: ReactNode;
+  className?: string;
+  padded?: boolean;
+}) {
+  const hasHead = title != null || icon != null || subtitle != null || action != null;
+  return (
+    <div className={`content-card${className ? ` ${className}` : ""}`}>
+      {hasHead ? (
+        <div className="content-card-head">
+          {icon ? (
+            <span className="content-card-icon" aria-hidden>
+              {icon}
+            </span>
+          ) : null}
+          <div className="content-card-head-text">
+            {title != null ? <p className="content-card-title">{title}</p> : null}
+            {subtitle != null ? <p className="content-card-subtitle">{subtitle}</p> : null}
+          </div>
+          {action ? <div className="content-card-action">{action}</div> : null}
+        </div>
+      ) : null}
+      <div className={padded ? "content-card-body" : undefined}>{children}</div>
+    </div>
+  );
+}
+
+/** A value + label tile (profile stats, rare-value summaries, …). */
+export function StatBlock({
+  value,
+  label,
+  icon,
+}: {
+  value: ReactNode;
+  label: string;
+  icon?: string;
+}) {
+  return (
+    <div className="stat-block">
+      <div className="stat-block-value">
+        {icon ? <span aria-hidden>{icon} </span> : null}
+        {value}
+      </div>
+      <div className="stat-block-label">{label}</div>
+    </div>
+  );
+}
+
+/** Friendly empty state with an icon and a muted line. */
+export function EmptyState({ icon = "📭", children }: { icon?: string; children: ReactNode }) {
+  return (
+    <div className="empty-state">
+      <div className="empty-state-icon" aria-hidden>
+        {icon}
+      </div>
+      <p className="muted" style={{ margin: 0 }}>
+        {children}
+      </p>
+    </div>
+  );
+}
+
+/** Online / offline pill with a status dot. */
+export function OnlineBadge({ online }: { online: boolean }) {
+  return (
+    <span className={`online-badge${online ? " online" : ""}`}>
+      <span className="online-dot" aria-hidden />
+      {online ? "Online" : "Offline"}
+    </span>
+  );
+}
+
+/** Leaderboard rank chip — medals for the top three, number otherwise. */
+export function RankBadge({ position }: { position: number }) {
+  const medal = position === 1 ? "🥇" : position === 2 ? "🥈" : position === 3 ? "🥉" : null;
+  return (
+    <span className={`rank-badge rank-${position <= 3 ? position : "n"}`}>
+      {medal ?? `#${position}`}
+    </span>
+  );
+}