feat: add drawing logic for free forge block without round head

Cad/BlockRawFreeForgeNoRoundHeadDrawer.cs

@@ -149,7 +149,7 @@ namespace CadParamPluging.Cad
             // 用户需求：
             // 1. 去掉最外侧的圆角 -> filletR 传入 innerFilletR (Updated per requirement)
             // 2. 横向闭合：水平线需延伸到中间框圆角结束的地方 (xSectionLeft + innerFilletR) 以实现无缝连接
-            // 3. 竖向不闭合：DrawBoxSideFrame 内部不 Closed，且不画连接处的竖线 (Now Closed=true in Helper)
+            // 3. 竖向不闭合：DrawBoxSideFrame 内部不 Closed，且不画连接处的竖线 (Now Closed=false in Helper)
             DrawBoxSideFrame(ctx, xInnerLeft, xSectionLeft + innerFilletR, oy, H, innerFilletR, isLeft: true);
 
             // 绘制右侧框线
@@ -483,8 +483,8 @@ namespace CadParamPluging.Cad
                  }
             }
 
-            // 关键修正：闭合多段线，确保与中间框接触的垂直边被画出来，消除圆角导致的缝隙
-            poly.Closed = true; 
+            // 关键修正：恢复为不闭合，以消除多出的垂直线
+            poly.Closed = false; 
 
             ctx.Style?.Apply(poly, DrawingStyleManager.Role.OutlineBold);
             ctx.Btr.AppendEntity(poly);