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/rankings/page.tsx

@@ -1,4 +1,5 @@
 import Link from "next/link";
+import { ContentCard, EmptyState, OnlineBadge, RankBadge } from "@/components/public/ui";
 import { avatarImageUrl } from "@/lib/format";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
@@ -10,13 +11,14 @@ type TopUser = {
   look: string;
   credits: number;
   rank: number;
+  online: string;
 };
 
 export default async function RankingsPage() {
   let users: TopUser[] = [];
   try {
     users = await prisma.user.findMany({
-      select: { username: true, look: true, credits: true, rank: true },
+      select: { username: true, look: true, credits: true, rank: true, online: true },
       orderBy: { credits: "desc" },
       take: 12,
     });
@@ -30,51 +32,47 @@ export default async function RankingsPage() {
   );
 
   return (
-    <main>
-      <div className="hero">
-        <h1 style={{ margin: "0 0 0.35rem" }}>Rankings</h1>
-        <p className="muted" style={{ margin: 0 }}>
-          The top 12 players ranked by credits.
-        </p>
-      </div>
+    <main style={{ display: "grid", gap: "1.5rem" }}>
+      <ContentCard icon="🏆" title="Rankings" subtitle="The top 12 players ranked by credits" />
 
-      {users.length === 0 ? (
-        <p className="muted">No players to rank yet.</p>
-      ) : (
-        <div className="grid cols-3">
-          {users.map((u, i) => {
-            const avatar = avatarImageUrl(imagerBase ?? "", u.look, { size: "m" });
-            return (
-              <div
-                key={u.username}
-                className="card hover"
-                style={{ display: "flex", gap: "1rem", alignItems: "center" }}
-              >
-                <span style={{ fontSize: "1.5rem", fontWeight: 800, minWidth: "2rem" }}>
-                  #{i + 1}
-                </span>
-                {/* eslint-disable-next-line @next/next/no-img-element */}
-                <img
-                  className="avatar"
-                  src={avatar}
-                  alt={`${u.username} avatar`}
-                  width={64}
-                  height={110}
-                />
-                <div style={{ minWidth: 0 }}>
-                  <h3 style={{ margin: "0 0 0.2rem" }}>
-                    <Link href={`/u/${u.username}`}>{u.username}</Link>
-                  </h3>
-                  <p className="currency" style={{ margin: 0 }}>
-                    <span className="coin credits">c</span>
-                    {u.credits.toLocaleString()}
-                  </p>
+      <ContentCard padded={users.length === 0}>
+        {users.length === 0 ? (
+          <EmptyState icon="🏆">No players to rank yet.</EmptyState>
+        ) : (
+          <div className="card-grid sm-2 lg-3" style={{ padding: "1rem" }}>
+            {users.map((u, i) => {
+              const avatar = avatarImageUrl(imagerBase ?? "", u.look, { size: "m" });
+              return (
+                <div
+                  key={u.username}
+                  className="card hover"
+                  style={{ display: "flex", gap: "0.9rem", alignItems: "center" }}
+                >
+                  <RankBadge position={i + 1} />
+                  {/* biome-ignore lint/performance/noImgElement: external avatar imager */}
+                  <img
+                    className="avatar"
+                    src={avatar}
+                    alt={`${u.username} avatar`}
+                    width={50}
+                    height={90}
+                  />
+                  <div style={{ minWidth: 0, flex: 1 }}>
+                    <h3 style={{ margin: "0 0 0.25rem", fontSize: "1rem" }}>
+                      <Link href={`/u/${u.username}`}>{u.username}</Link>
+                    </h3>
+                    <p className="currency" style={{ margin: "0 0 0.3rem" }}>
+                      <span className="coin credits">c</span>
+                      {u.credits.toLocaleString()}
+                    </p>
+                    <OnlineBadge online={u.online === "1"} />
+                  </div>
                 </div>
-              </div>
-            );
-          })}
-        </div>
-      )}
+              );
+            })}
+          </div>
+        )}
+      </ContentCard>
     </main>
   );
 }