feat: ATM10-Statistikportal

Statistikportal für den All-the-Mods-10-Server (Minecraft 1.21.1, NeoForge 21.1):

- mod/: serverseitige NeoForge-Mod atmstats – Ereignisse, Live-Zähler, Servergesundheit,
  FTB-Dateien; Outbox auf der Festplatte, signierter gzip-Versand per HTTPS mit Backoff
- backend/: Fastify + PostgreSQL – idempotenter Ingest, Projektionen, Parser für SNBT,
  FTB Quests/Teams, world/stats, world/advancements und latest.log; Ranglisten, Snapshots,
  Retention, öffentliche API, SSE-Live-Updates, Admin mit argon2/CSRF, SFTP-Worker
- web/: Next.js-Dashboard – Übersicht, Ranglisten, Spielerprofile, ATM10, Server,
  Datenquellen, Verwaltung
- shared/: Protokoll v1 und API-Typen; tools/: Simulator, Log-Anonymisierer, RCON-Client
- deploy/: Docker Compose hinter Traefik, Backup; docs/: Architektur, Datenquellen, Betrieb

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/app/leaderboards/[board]/page.tsx

@@ -0,0 +1,74 @@
+import type { LeaderboardDto, Period } from '@atm/shared/api';
+import type { Metadata } from 'next';
+import Link from 'next/link';
+import { notFound } from 'next/navigation';
+import { PeriodTabs } from '@/components/PeriodTabs';
+import { PlayerHead } from '@/components/PlayerHead';
+import { ApiDown, EmptyState, PageTitle } from '@/components/States';
+import { apiFind } from '@/lib/api';
+import { formatUnit } from '@/lib/format';
+
+export const dynamic = 'force-dynamic';
+
+type Props = { params: Promise<{ board: string }>; searchParams: Promise<{ period?: string }> };
+
+const PERIOD_TEXT: Record<Period, string> = {
+  all: 'über die gesamte Spielzeit',
+  '30d': 'Zuwachs der letzten 30 Tage',
+  '7d': 'Zuwachs der letzten 7 Tage',
+};
+
+export async function generateMetadata({ params }: Props): Promise<Metadata> {
+  const { board } = await params;
+  const data = await apiFind<LeaderboardDto>(`/api/leaderboards/${encodeURIComponent(board)}`).catch(() => null);
+  return { title: data?.board.title ?? 'Rangliste' };
+}
+
+export default async function BoardPage({ params, searchParams }: Props) {
+  const { board } = await params;
+  const raw = (await searchParams).period;
+  const period: Period = raw === '7d' || raw === '30d' ? raw : 'all';
+  let data: LeaderboardDto | null;
+  try {
+    data = await apiFind<LeaderboardDto>(`/api/leaderboards/${encodeURIComponent(board)}?period=${period}`);
+  } catch {
+    return <ApiDown />;
+  }
+  if (!data) notFound();
+  const max = Math.max(...data.entries.map((e) => e.value), 1);
+
+  return (
+    <>
+      <p className="text-sm mb-2">
+        <Link href="/leaderboards" className="text-stone-3 hover:text-stone">Alle Ranglisten</Link>
+      </p>
+      <PageTitle title={data.board.title}>
+        {data.board.description}, {PERIOD_TEXT[period]}.
+      </PageTitle>
+      <div className="mb-6">
+        <PeriodTabs base={`/leaderboards/${data.board.id}`} active={period} />
+      </div>
+      {data.entries.length === 0 ? (
+        <EmptyState title="Noch keine Einträge">
+          {period === 'all' ? 'Sobald Spieler Werte in dieser Kategorie haben, erscheinen sie hier.' : 'In diesem Zeitraum hat sich niemand verbessert.'}
+        </EmptyState>
+      ) : (
+        <ol className="rounded-lg bg-slate-1 border border-slate-2 divide-y divide-slate-2">
+          {data.entries.map((e) => (
+            <li key={e.uuid} className="flex items-center gap-3 px-4 py-2.5">
+              <span className={`w-8 text-right font-semibold tabular-nums ${e.rank <= 3 ? 'text-gold' : 'text-stone-3'}`}>{e.rank}</span>
+              <PlayerHead uuid={e.uuid} name={e.name} size={28} />
+              <Link href={`/players/${e.name ?? e.uuid}`} className="w-40 truncate hover:text-gold">
+                {e.name ?? 'Unbekannt'}
+              </Link>
+              <span className="hidden sm:block flex-1 h-1.5 rounded-full bg-slate-2 overflow-hidden" aria-hidden>
+                <span className="block h-full rounded-full bg-gold-dim" style={{ width: `${(e.value / max) * 100}%` }} />
+              </span>
+              <span className="ml-auto sm:ml-0 sm:w-28 text-right tabular-nums">{formatUnit(e.value, data.board.unit)}</span>
+            </li>
+          ))}
+        </ol>
+      )}
+    </>
+  );
+}