refactor(角色): 修改HCN技能效果为储能并随机选择初始角色

将HCN的召唤物死亡效果从恢复生命值改为储能10点
修改初始角色选择逻辑为随机选择
更新角色卡牌描述以匹配新技能效果

components/CharacterCards/HCN.tscn

@@ -20,7 +20,7 @@ theme_override_styles/panel = SubResource("StyleBoxFlat_1yfsg")
 displayName = "氰化氢"
 slogan = "微量便可颠覆生机"
 avatar = ExtResource("2_1yfsg")
-description = "召唤物死亡时为自身恢复生命值。"
+description = "在召唤物死亡时储能。"
 fields = Array[int]([18, 27])
 fieldValues = Array[float]([5.0, 1.0])
 clickToRebuild = true

scripts/Contents/Characters/HCN.gd

@@ -1,4 +1,4 @@
 extends PlayerBase
 
 func summoned(entity: SummonBase):
-	entity.died.connect(func(): tryHeal(5))
+	entity.died.connect(func(): storeEnergy(10))

scripts/Contents/Panels/Starter.gd

@@ -33,7 +33,7 @@ static var GAMEMODE_MAP_WAVE = [Wave.WAVE_NORMAL, Wave.WAVE_BOSSRUSH, Wave.WAVE_
 static var START_CHARACTERS = ["MuyangDog", "Lynx", "HCN"]
 static var buildingShader: bool = true
 static var selectingFeed: bool = true
-static var selectedCharacter: String = START_CHARACTERS[1]
+static var selectedCharacter: String = MathTool.randomChoiceFrom(START_CHARACTERS)
 
 @rpc("any_peer")
 func mutexPlayer(player: String):