feat(战斗系统): 改进敌人生成逻辑以围绕玩家位置生成

修改Wave.spawn方法以接受中心点参数，使敌人生成位置围绕玩家
在Starter和MakeFeed面板中调用spawnWave时计算玩家中心位置
重构EntityBase添加getPlayers方法获取所有玩家实体
重命名WorldManager.nextWave为doNextWave以更清晰表达意图

scripts/Contents/Panels/MakeFeed.gd

@@ -50,7 +50,11 @@ func updateValue():
 	countLabel.text = str(UIState.player.fields[FieldStore.Entity.FEED_COUNT_CAN_MADE] - selectedCount)
 	needBB.count = refreshNeedBaseballCount
 func finish():
-	WorldManager.rootNode.spawnWave()
+	var center = Vector2.ZERO
+	for player in EntityBase.getPlayers():
+		center += player.position
+	center /= len(EntityBase.getPlayers())
+	WorldManager.rootNode.spawnWave(center)
 	UIState.closeCurrentPanel()
 func regenerateCards():
 	updateValue()

scripts/Contents/Panels/Starter.gd

@@ -64,7 +64,7 @@ func startSingleplayerGame():
 	MultiplayerState.isMultiplayer = false
 	MultiplayerState.playerName = playerNameInput.text
 	EntityBase.generatePlayer(playerNameInput.text)
-	WorldManager.rootNode.spawnWave()
+	WorldManager.rootNode.spawnWave(Vector2.ZERO)
 	UIState.closeCurrentPanel()
 
 func _ready():

scripts/Contents/Wave.gd

@@ -82,13 +82,13 @@ static func entityCountOf(wave: Wave) -> int:
 		elif !hasBoss():
 			return randi_range(ceil(wave.minCount), floor(wave.maxCount * (1 + GameRule.entityCountBoostPerWave * current)))
 	return 0
-static func spawn() -> Array:
+static func spawn(center: Vector2) -> Array:
 	var result: Array = []
 	for i in range(len(data)):
 		var wave: Wave = data[i]
 		for j in range(entityCountOf(wave)):
 			var currentWave = wave.duplicate()
-			currentWave.entityPosition = MathTool.randv2_range(500)
+			currentWave.entityPosition = MathTool.randv2_range(500) + center
 			result.append(currentWave)
 	return result
 static func next(waves: Array):