feat: 重构棋盘逻辑和游戏流程,将引擎版本提升至4.3

- 重构了 VirtualBoard 类，优化了棋盘操作和事件处理
- 重写了 ChessPiece 类，增加了事件处理和虚拟棋子逻辑
- 更新了 ChessGame 控制器，增加了结束回合功能和对话框
- 调整了场景布局和资源引用
- 清理了冗余代码和注释

Main.tscn

@@ -1,7 +1,7 @@
 [gd_scene load_steps=3 format=3 uid="uid://boa4od72355o4"]
 
 [ext_resource type="Script" path="res://Main.cs" id="1_h4cv2"]
-[ext_resource type="Theme" uid="uid://c53fg2fg071yp" path="res://Asserts/defalutTheme.tres" id="2_8jwne"]
+[ext_resource type="Theme" uid="uid://intlbeu8h82r" path="res://Asserts/defaultTheme.tres" id="2_afihr"]
 
 [node name="Main" type="Node2D"]
 script = ExtResource("1_h4cv2")
@@ -9,7 +9,7 @@ script = ExtResource("1_h4cv2")
 [node name="Control" type="Control" parent="."]
 layout_mode = 3
 anchors_preset = 0
-theme = ExtResource("2_8jwne")
+theme = ExtResource("2_afihr")
 
 [node name="SignlePlayer" type="Button" parent="Control"]
 layout_mode = 0
@@ -29,21 +29,21 @@ text = "多人"
 
 [node name="Label" type="Label" parent="Control"]
 layout_mode = 0
-offset_left = 210.0
-offset_top = 312.0
-offset_right = 520.0
-offset_bottom = 498.0
+offset_left = 191.0
+offset_top = 265.0
+offset_right = 501.0
+offset_bottom = 451.0
+theme_override_font_sizes/font_size = 48
 text = "中国象棋"
 horizontal_alignment = 1
 vertical_alignment = 1
 
 [node name="Setting" type="Button" parent="Control"]
-visible = false
 layout_mode = 0
-offset_left = 249.0
-offset_top = 1034.0
-offset_right = 432.0
-offset_bottom = 1201.0
+offset_left = 239.0
+offset_top = 967.0
+offset_right = 450.0
+offset_bottom = 1150.0
 text = "设置"
 
 [connection signal="pressed" from="Control/SignlePlayer" to="." method="GoToSignlePlayer"]