feat(web): 提取共享基础组件 — dayjs/format/EntityName/FilterBar/PageContainer/DrawerForm

- utils/dayjs.ts: 集中初始化 relativeTime 插件 + zh-cn locale
- utils/format.ts: formatDate/formatDateTime/formatRelative/calcAge
- components/EntityName.tsx: UUID→姓名兜底显示
- components/FilterBar.tsx: 统一筛选栏容器
- components/PageContainer.tsx: 统一页面容器（标题+筛选+表格+暗色模式）
- components/DrawerForm.tsx: 抽屉式表单容器（分组+双列网格）
- AlertList.tsx: 迁移到集中 dayjs 导入

apps/web/src/components/EntityName.tsx

@@ -0,0 +1,23 @@
+import { Tooltip, Typography } from 'antd';
+
+interface EntityNameProps {
+  name?: string | null;
+  id?: string;
+  fallbackLabel?: string;
+}
+
+export function EntityName({ name, id, fallbackLabel = '未知' }: EntityNameProps) {
+  if (name) return <span>{name}</span>;
+
+  if (id) {
+    return (
+      <Tooltip title={`ID: ${id.slice(0, 8)}...`}>
+        <Typography.Text type="secondary" style={{ cursor: 'help' }}>
+          {fallbackLabel}
+        </Typography.Text>
+      </Tooltip>
+    );
+  }
+
+  return <Typography.Text type="secondary">{fallbackLabel}</Typography.Text>;
+}