feat(panel): implement player leaderboards page

Replaces the placeholder with a real leaderboard view showing top 10
players by level, wealth, and net worth. Reuses the existing /api/stats
endpoint which players already have access to.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

panel/src/App.tsx

@@ -7,6 +7,7 @@ import Settings from "./pages/Settings";
 import Users from "./pages/Users";
 import Items from "./pages/Items";
 import PlaceholderPage from "./pages/PlaceholderPage";
+import Leaderboards from "./pages/Leaderboards";
 import NotEnrolled from "./pages/NotEnrolled";
 import PlayerDashboard from "./pages/PlayerDashboard";
 import { GameLobby } from "./games/GameLobby";
@@ -33,10 +34,6 @@ const placeholders: Record<string, { title: string; description: string }> = {
         title: "Transactions",
         description: "Browse the economy transaction log with filtering by user, type, and date.",
     },
-    leaderboards: {
-        title: "Leaderboards",
-        description: "View top players by level, wealth, and net worth.",
-    },
 };
 
 function AppRoutes() {
@@ -78,7 +75,7 @@ function AppRoutes() {
 
                 {/* Player routes */}
                 <Route path="/dashboard" element={<PlayerDashboard userId={user.discordId} />} />
-                <Route path="/leaderboards" element={<PlaceholderPage {...placeholders.leaderboards} />} />
+                <Route path="/leaderboards" element={<Leaderboards />} />
 
                 {/* Game routes (both roles) */}
                 <Route path="/games" element={<GameLobby />} />

panel/src/pages/Leaderboards.tsx

@@ -0,0 +1,142 @@
+import { useState, useEffect } from "react";
+import { Trophy, Crown, Gem, Loader2, AlertTriangle } from "lucide-react";
+import { get } from "../lib/api";
+import { cn } from "../lib/utils";
+
+interface LeaderboardData {
+    topLevels: Array<{ username: string; level: number }>;
+    topWealth: Array<{ username: string; balance: string }>;
+    topNetWorth: Array<{ username: string; netWorth: string }>;
+}
+
+function formatNumber(n: number | string): string {
+    const num = typeof n === "string" ? parseFloat(n) : n;
+    if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(1)}M`;
+    if (num >= 1_000) return `${(num / 1_000).toFixed(1)}K`;
+    return num.toLocaleString();
+}
+
+function LeaderboardColumn({
+    title,
+    icon: Icon,
+    entries,
+    valueKey,
+    valuePrefix,
+}: {
+    title: string;
+    icon: React.ComponentType<{ className?: string }>;
+    entries: Array<{ username: string; [k: string]: unknown }>;
+    valueKey: string;
+    valuePrefix?: string;
+}) {
+    return (
+        <div className="bg-card rounded-xl">
+            <div className="flex items-center gap-2 px-5 py-4">
+                <Icon className="w-4 h-4 text-primary" />
+                <h3 className="text-sm font-display font-semibold">{title}</h3>
+            </div>
+            <div className="space-y-0">
+                {entries.length === 0 && (
+                    <div className="px-5 py-4 text-sm text-text-tertiary">No data</div>
+                )}
+                {entries.slice(0, 10).map((entry, i) => (
+                    <div
+                        key={entry.username}
+                        className="flex items-center justify-between px-5 py-3 hover:bg-raised/30 transition-colors rounded-lg mx-2 mb-1"
+                    >
+                        <div className="flex items-center gap-3">
+                            <span
+                                className={cn(
+                                    "w-6 text-xs font-mono font-medium text-right",
+                                    i === 0
+                                        ? "text-gold"
+                                        : i === 1
+                                        ? "text-text-secondary"
+                                        : i === 2
+                                        ? "text-warning"
+                                        : "text-text-tertiary"
+                                )}
+                            >
+                                #{i + 1}
+                            </span>
+                            <span className="text-sm">{entry.username}</span>
+                        </div>
+                        <span className="text-sm font-mono text-text-secondary">
+                            {valuePrefix}
+                            {formatNumber(entry[valueKey] as string | number)}
+                        </span>
+                    </div>
+                ))}
+            </div>
+        </div>
+    );
+}
+
+export default function Leaderboards() {
+    const [leaderboards, setLeaderboards] = useState<LeaderboardData | null>(null);
+    const [loading, setLoading] = useState(true);
+    const [error, setError] = useState<string | null>(null);
+
+    useEffect(() => {
+        get<{ leaderboards?: LeaderboardData }>("/api/stats")
+            .then((data) => {
+                setLeaderboards(data.leaderboards ?? null);
+            })
+            .catch(() => setError("Failed to load leaderboards"))
+            .finally(() => setLoading(false));
+    }, []);
+
+    if (loading) {
+        return (
+            <div className="flex items-center justify-center py-32">
+                <Loader2 className="w-6 h-6 animate-spin text-primary" />
+            </div>
+        );
+    }
+
+    if (error) {
+        return (
+            <div className="flex items-center justify-center py-32">
+                <div className="text-center">
+                    <AlertTriangle className="w-8 h-8 text-warning mx-auto mb-3" />
+                    <p className="text-sm text-text-tertiary">{error}</p>
+                </div>
+            </div>
+        );
+    }
+
+    if (!leaderboards) {
+        return (
+            <div className="flex items-center justify-center py-32">
+                <p className="text-sm text-text-tertiary">No leaderboard data available</p>
+            </div>
+        );
+    }
+
+    return (
+        <div>
+            <h1 className="font-display text-lg font-semibold mb-6">Leaderboards</h1>
+            <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
+                <LeaderboardColumn
+                    title="Top Levels"
+                    icon={Trophy}
+                    entries={leaderboards.topLevels}
+                    valueKey="level"
+                    valuePrefix="Lv. "
+                />
+                <LeaderboardColumn
+                    title="Top Wealth"
+                    icon={Crown}
+                    entries={leaderboards.topWealth}
+                    valueKey="balance"
+                />
+                <LeaderboardColumn
+                    title="Top Net Worth"
+                    icon={Gem}
+                    entries={leaderboards.topNetWorth}
+                    valueKey="netWorth"
+                />
+            </div>
+        </div>
+    );
+}