修复温差图画框逻辑：设置线径为1并优化初始框大小设置

Windows/CS/Framework4.0/Toprie/Toprie/Setting.cs

@@ -650,7 +650,10 @@ namespace JoyD.Windows.CS
                 }
                 
                 // 获取相对于图像的坐标作为矩形起始点
-                _rectangleStartPoint = ControlPointToImagePoint(e.Location);
+                Point imagePoint = ControlPointToImagePoint(e.Location);
+                
+                // 按下鼠标时初始框大小即为笔块大小
+                _rectangleStartPoint = imagePoint;
                 _isDrawingRectangle = true;
                 return;
             }
@@ -1350,8 +1353,8 @@ namespace JoyD.Windows.CS
                                 // 绘制填充矩形
                                 g.FillRectangle(new SolidBrush(fillColor), rect);
                                 
-                                // 绘制矩形边框
-                                using (Pen pen = new Pen(selectedColor, _currentBrushSize))
+                                // 绘制矩形边框，线径固定为1以更精确控制绘制逻辑
+                                using (Pen pen = new Pen(selectedColor, 1))
                                 {                                      
                                     g.DrawRectangle(pen, rect);
                                 }