加载骨架屏

Create a loading skeleton screen for a dashboard page. Include a skeleton navbar, 4 stat cards with placeholder numbers, a large chart placeholder, and a data table placeholder with 5 rows. Use shadcn/ui Skeleton component and Tailwind CSS. Add a shimmer/pulse animation and ensure the skeleton layout matches the real content dimensions to avoid layout shift.

为仪表盘页面创建一个加载骨架屏。包含骨架导航栏、4 个带占位数字的统计卡片、一个大型图表占位符和 5 行数据表格占位符。使用 shadcn/ui Skeleton 组件和 Tailwind CSS。添加闪光/脉冲动画，并确保骨架布局与真实内容尺寸一致以避免布局偏移。