Add RankingManager and integrate RR system

Introduce a new RankingManager that implements a per-round Rank Rating (RR) system (placement + kill-based scoring, placement games, kill caps and RR interpolation). Wire the manager into the plugin (SpeedHG): add field + initialization. Integrate into GameManager: call startRound at game start, registerRoundKill on kills, and onPlayerResult for eliminated players and the winner; adjust some stats calls (addLoss/addWin kept alongside ranking updates). Add corresponding English language messages for placement progress and result notifications.

src/main/kotlin/club/mcscrims/speedhg/game/GameManager.kt

@@ -205,6 +205,8 @@ class GameManager(
 			player.sendMsg( "game.started" )
 		}
 
+		plugin.rankingManager.startRound( Bukkit.getOnlinePlayers() )
+
 		Bukkit.getOnlinePlayers().forEach { player ->
 			player.sendMsg( "game.invincibility-start", "time" to invincibilityTime.toString() )
 		}
@@ -247,13 +249,14 @@ class GameManager(
 		player.gameMode = GameMode.SPECTATOR
 
 		plugin.statsManager.addDeath( player.uniqueId )
-		plugin.statsManager.adjustScrimScore( player.uniqueId, -25 ) // Elo-Verlust
+		plugin.statsManager.addLoss( player.uniqueId )
+		plugin.rankingManager.onPlayerResult( player, isWinner = false )
 
 		if ( killer != null )
 		{
 			killer.exp += 0.5f
 			plugin.statsManager.addKill( killer.uniqueId )
-			plugin.statsManager.adjustScrimScore( killer.uniqueId, +15 ) // Elo-Gewinn
+			plugin.rankingManager.registerRoundKill( killer.uniqueId )
 		}
 
 		player.inventory.contents.filterNotNull().forEach {
@@ -296,7 +299,7 @@ class GameManager(
 			if ( p.uniqueId == winnerUUID )
 			{
 				plugin.statsManager.addWin( p.uniqueId )
-				plugin.statsManager.adjustScrimScore( p.uniqueId, +50 ) // Elo-Bonus für Win
+				plugin.rankingManager.onPlayerResult( p, isWinner = true )
 			}
 		}