feat: implement leaderboard page with top players, teams, and high scores

- Added a new leaderboard route with server-side loading for top players, teams, and recent high scores.
- Created a new Svelte component for the leaderboard UI, including tabs for players, teams, and scores.
- Implemented ELO ranking display and win/loss statistics for players.
- Added functionality to display team wins and member counts.
- Included recent high scores with player context and map details.
- Enhanced team management features in the teams route, including renaming and member management with permission checks.

src/lib/components/Sidebar.svelte

@@ -7,7 +7,8 @@
 		{ href: '/', label: 'Dashboard', icon: '⌂' },
 		{ href: '/matches', label: 'Matches', icon: '⚔' },
 		{ href: '/mappools', label: 'Mappools', icon: '♫' },
-		{ href: '/teams', label: 'Teams', icon: '⚑' }
+		{ href: '/teams', label: 'Teams', icon: '⚑' },
+		{ href: '/leaderboard', label: 'Leaderboard', icon: '🏆' }
 	];
 
 	function isActive(href: string) {