feat: 优化UI操作逻辑，增加退出游戏按钮

scenes/settings.tscn

@@ -96,10 +96,10 @@ offset_bottom = 60.0
 theme_override_font_sizes/font_size = 25
 
 [node name="SaveButton" type="Button" parent="." unique_id=1377249836]
-offset_left = 150.0
-offset_top = 1321.0
-offset_right = 314.0
-offset_bottom = 1398.0
+offset_left = 147.0
+offset_top = 1315.0
+offset_right = 311.0
+offset_bottom = 1392.0
 theme_override_fonts/font = ExtResource("2_6wm04")
 theme_override_font_sizes/font_size = 30
 text = "保存设置"
@@ -120,7 +120,7 @@ offset_right = 550.0
 offset_bottom = 1394.0
 theme_override_fonts/font = ExtResource("2_6wm04")
 theme_override_font_sizes/font_size = 30
-text = "取消"
+text = "返回"
 
 [node name="LoadButton" type="Button" parent="." unique_id=2015694853]
 offset_left = 135.0