处理mac打包后粘贴图片缩略图不可见的问题，处理历史history不可见问题

@@ -2197,10 +2197,41 @@ class ImageGeneratorWindow(QMainWindow):
                 except Exception as e:
                     self.logger.error(f"创建缩略图失败: {file_path}, 错误: {str(e)}", exc_info=True)
 
-            # 强制刷新布局和滚动区域（macOS 打包环境下可能需要）
+            # 强制刷新布局和滚动区域
             self.img_container.adjustSize()
+            self.img_layout.activate()
             self.img_scroll.update()
 
+            # === 诊断日志：排查缩略图不可见问题 ===
+            self.logger.info(f"[诊断] img_layout.count = {self.img_layout.count()}")
+            self.logger.info(f"[诊断] img_container.size = {self.img_container.size().width()}x{self.img_container.size().height()}")
+            self.logger.info(f"[诊断] img_container.isVisible = {self.img_container.isVisible()}")
+            self.logger.info(f"[诊断] img_scroll.size = {self.img_scroll.size().width()}x{self.img_scroll.size().height()}")
+            self.logger.info(f"[诊断] img_scroll.isVisible = {self.img_scroll.isVisible()}")
+            self.logger.info(f"[诊断] img_scroll.widget = {self.img_scroll.widget()}")
+            self.logger.info(f"[诊断] img_scroll.widgetResizable = {self.img_scroll.widgetResizable()}")
+            for i in range(self.img_layout.count()):
+                item = self.img_layout.itemAt(i)
+                w = item.widget()
+                if w:
+                    self.logger.info(
+                        f"[诊断] layout[{i}]: widget={w.__class__.__name__}, "
+                        f"size={w.size().width()}x{w.size().height()}, "
+                        f"sizeHint={w.sizeHint().width()}x{w.sizeHint().height()}, "
+                        f"visible={w.isVisible()}, "
+                        f"geometry={w.geometry()}"
+                    )
+                    # 检查子 widget
+                    for child in w.findChildren(QLabel):
+                        pm = child.pixmap()
+                        self.logger.info(
+                            f"[诊断]   QLabel: size={child.size().width()}x{child.size().height()}, "
+                            f"visible={child.isVisible()}, "
+                            f"hasPixmap={pm is not None and not pm.isNull() if pm else False}"
+                        )
+                else:
+                    self.logger.info(f"[诊断] layout[{i}]: spacer/stretch")
+
         except Exception as e:
             self.logger.error(f"更新图片预览失败: {str(e)}", exc_info=True)