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

Scenes/Menu.tscn

@@ -1,7 +1,7 @@
 [gd_scene load_steps=3 format=3 uid="uid://cl8nkm6j8s8jh"]
 
 [ext_resource type="Script" path="res://Scripts/Controllers/Menu.cs" id="1_chiyi"]
-[ext_resource type="Theme" uid="uid://c53fg2fg071yp" path="res://Asserts/defalutTheme.tres" id="1_sg40w"]
+[ext_resource type="Theme" uid="uid://intlbeu8h82r" path="res://Asserts/defaultTheme.tres" id="1_mkeko"]
 
 [node name="Menu" type="Control"]
 layout_mode = 3
@@ -10,7 +10,7 @@ anchor_right = 1.0
 anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
-theme = ExtResource("1_sg40w")
+theme = ExtResource("1_mkeko")
 script = ExtResource("1_chiyi")
 metadata/_edit_horizontal_guides_ = [141.0]
 
@@ -63,9 +63,10 @@ offset_bottom = 1198.0
 
 [node name="ItemList" type="ItemList" parent="Server"]
 layout_mode = 0
-offset_top = 120.0
-offset_right = 663.0
-offset_bottom = 965.0
+offset_left = 15.0
+offset_top = 214.0
+offset_right = 678.0
+offset_bottom = 1059.0
 
 [node name="ConnectServer" type="Button" parent="Server"]
 layout_mode = 0
@@ -113,10 +114,10 @@ size = Vector2i(200, 118)
 
 [node name="URL" type="LineEdit" parent="."]
 layout_mode = 0
-offset_left = 22.0
-offset_top = 1166.0
-offset_right = 662.0
-offset_bottom = 1247.0
+offset_left = 37.0
+offset_top = 290.0
+offset_right = 677.0
+offset_bottom = 371.0
 
 [connection signal="pressed" from="Home" to="." method="goToHome"]
 [connection signal="pressed" from="Name/Button" to="." method="EnterName"]