feat: live game tiles on homepage + bot spectating

- GET /v1/games/live returns all active games with both players assigned,
  including current FEN (computed server-side via chess.js)
- LiveGames component on homepage: mini chessboard tiles (160px) that
  auto-refresh every 3s, clickable to join as spectator
- Tournament page: 'Zuschauen' button for non-players on ongoing rounds
  (bot vs bot, human vs human, human vs bot all spectatable)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/src/app/page.tsx

@@ -3,6 +3,7 @@
 import CreateGame from "@/components/home/CreateGame";
 import JoinGame from "@/components/home/JoinGame";
 import PublicGames from "@/components/home/PublicGames/PublicGames";
+import LiveGames from "@/components/home/LiveGames";
 import Link from "next/link";
 import { useSession } from "@/context/session";
 
@@ -78,6 +79,9 @@ export default function Home() {
 
       </div>
 
+      {/* Laufende Partien – Live-Kacheln */}
+      <LiveGames />
+
       {/* Öffentliche Spiele + Beitreten */}
       <div className={`grid gap-6 grid-cols-1 ${isLoggedIn ? "lg:grid-cols-3" : ""}`}>
         <div className={isLoggedIn ? "lg:col-span-2" : ""}>

client/src/app/tournament/[code]/page.tsx

@@ -242,6 +242,11 @@ export default function TournamentDetailPage() {
                               Spielen
                             </Link>
                           )}
+                          {!isMyGame && g.gameCode && !g.result && (
+                            <Link href={`/${g.gameCode}`} className="btn btn-xs btn-outline">
+                              Zuschauen
+                            </Link>
+                          )}
                           {g.gameCode && g.result && (
                             <Link href={`/${g.gameCode}`} className="btn btn-xs btn-ghost">
                               Ansehen

client/src/components/home/LiveGames.tsx

@@ -0,0 +1,51 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { Chessboard } from "react-chessboard";
+import Link from "next/link";
+import { fetchLiveGames, type LiveGameEntry } from "@/lib/game";
+
+export default function LiveGames() {
+  const [games, setGames] = useState<LiveGameEntry[]>([]);
+
+  useEffect(() => {
+    let mounted = true;
+    const load = async () => {
+      const data = await fetchLiveGames();
+      if (mounted) setGames(data);
+    };
+    load();
+    const interval = setInterval(load, 3000);
+    return () => { mounted = false; clearInterval(interval); };
+  }, []);
+
+  if (!games.length) return null;
+
+  return (
+    <div>
+      <h2 className="text-xl font-bold mb-3">Laufende Partien</h2>
+      <div className="grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5 gap-3">
+        {games.map((game) => (
+          <Link
+            key={game.code}
+            href={`/${game.code}`}
+            className="card bg-base-200 hover:bg-base-300 transition-colors overflow-hidden"
+          >
+            <Chessboard
+              position={game.fen}
+              boardWidth={160}
+              arePiecesDraggable={false}
+              customDarkSquareStyle={{ backgroundColor: "#4b7399" }}
+              customLightSquareStyle={{ backgroundColor: "#eae9d2" }}
+            />
+            <div className="px-2 py-1.5 flex flex-col gap-0.5">
+              <span className="text-xs font-semibold truncate">{game.black?.name}</span>
+              <span className="text-xs opacity-40 text-center leading-none">vs</span>
+              <span className="text-xs font-semibold truncate">{game.white?.name}</span>
+            </div>
+          </Link>
+        ))}
+      </div>
+    </div>
+  );
+}

client/src/lib/game.ts

@@ -35,6 +35,25 @@ export const fetchActiveGame = async (code: string) => {
     }
 };
 
+export type LiveGameEntry = {
+    code: string;
+    white: { name?: string };
+    black: { name?: string };
+    fen: string;
+    timeControl?: number;
+    tournamentCode?: string;
+};
+
+export const fetchLiveGames = async (): Promise<LiveGameEntry[]> => {
+    try {
+        const res = await fetch(`${API_URL}/v1/games/live`, { cache: "no-store" });
+        if (res.ok) return res.json();
+    } catch (err) {
+        console.error(err);
+    }
+    return [];
+};
+
 export const fetchPublicGames = async () => {
     try {
         const res = await fetch(`${API_URL}/v1/games`, { cache: "no-store" });