refactor(UI): 调整技能图标布局并优化冷却效果

修改技能图标面板的锚点设置以改善布局
将冷却进度着色器逻辑反转并优化视觉效果
统一材质管理方式，移除重复的材质复制

components/Scenes/UI.tscn

@@ -119,7 +119,6 @@ _data = {
 }
 
 [sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_12otr"]
-content_margin_right = 10.0
 
 [node name="UI" type="CanvasLayer"]
 process_mode = 3
@@ -252,12 +251,13 @@ libraries = {
 
 [node name="skills" type="PanelContainer" parent="root"]
 layout_mode = 1
-anchors_preset = 6
-anchor_left = 1.0
+anchors_preset = -1
+anchor_left = 0.97
 anchor_top = 0.5
-anchor_right = 1.0
+anchor_right = 0.97
 anchor_bottom = 0.5
-offset_left = -10.0
+offset_left = 0.399902
+offset_right = 0.399902
 grow_horizontal = 0
 grow_vertical = 2
 theme_override_styles/panel = SubResource("StyleBoxEmpty_12otr")