feat(角色卡片): 添加新角色卡片资源并优化显示逻辑

添加猞猁、牧羊犬和氰化氢的角色卡片资源
优化卡片选中状态的动画显示逻辑
调整卡片样式和主题配置
移除冗余的panel节点引用

scripts/Contents/Panels/Starter.gd

@@ -210,3 +210,7 @@ func rebuildInfo():
 				getCurrentSelectedCharacter().animator.play("show")
 		)
 		charactersBox.add_child(card)
+		if selectedCharacter == card.name:
+			card.animator.play("show")
+		else:
+			card.animator.play("hide")

scripts/Structs/Character.gd

@@ -12,7 +12,6 @@ signal select()
 @export var clickToRebuild: bool = false
 @export var borderOpacity: float = 0
 
-@onready var panel: PanelContainer = $%panel
 @onready var avatarTexture: TextureRect = $%avatarTexture
 @onready var nameLebel: Label = $%nameLabel
 @onready var descriptionLabel: Label = $%descriptionLabel
@@ -20,10 +19,10 @@ signal select()
 @onready var animator: AnimationPlayer = $%animator
 
 var watcher: Watcher = Watcher.new(false)
-@onready var panelStyleBox: StyleBoxFlat = panel.get_theme_stylebox("panel").duplicate()
+@onready var panelStyleBox: StyleBoxFlat = get_theme_stylebox("panel").duplicate()
 
 func _ready():
-	panel.add_theme_stylebox_override("panel", panelStyleBox)
+	add_theme_stylebox_override("panel", panelStyleBox)
 	watcher.changed.connect(rebuildInfo)
 	gui_input.connect(
 		func(event):