fix(shot): include sidebar in background clip region for blur effect

In recording/scrollshot modes, the background is only drawn within
the toolbar clip area to avoid blocking mouse passthrough. When the
AI assistant panel (sidebar) is shown, it falls outside the toolbar
clip rect, so its blur backdrop has no background pixels to sample
from.

Extend the clip region to also cover the sidebar geometry when it is
visible, using QRegion to combine both rects.

bug: https://pms.uniontech.com/bug-view-356057.html

Author: dengzhongyuan365-dev

src/main_window.cpp

@@ -4802,12 +4802,20 @@ void MainWindow::paintEvent(QPaintEvent *event)
         // 录屏/滚动截图模式：只在工具栏区域绘制背景
         // 不全屏绘制，避免影响鼠标穿透
         if (m_toolBar && m_toolBar->isVisible()) {
+            QRegion clipRegion;
             QRect toolBarRect = m_toolBar->geometry();
             toolBarRect.adjust(-20, -20, 20, 20);
-            
+            clipRegion += toolBarRect;
+            // 二级工具栏（如AI助手面板）也需要背景模糊效果
+            if (m_sideBar && m_sideBar->isVisible()) {
+                QRect sideBarRect = m_sideBar->geometry();
+                sideBarRect.adjust(-20, -20, 20, 20);
+                clipRegion += sideBarRect;
+            }
+
             painter.setRenderHint(QPainter::Antialiasing, true);
             m_backgroundPixmap.setDevicePixelRatio(m_pixelRatio);
-            painter.setClipRect(toolBarRect);
+            painter.setClipRegion(clipRegion);
             painter.drawPixmap(backgroundRect, m_backgroundPixmap);
             painter.setClipping(false);
         }