feat: Drawer 响应式默认宽度与拖拽调整，统计卡片上下布局优化

Drawer 宽度从固定百分比改为按视口响应式默认值（6段断点），宽屏占比更小、窄屏占比更大。

启用 TDesign sizeDraggable 原生拖拽调整能力，配置 min/max 视口安全边界，不持久化拖拽宽度。

概览统计卡片改为 TDesign Statistic 上下布局（与 SummaryCards 一致），提升窄屏视觉体验。

Drawer header 间距调大，MutationObserver polyfill 补全。

tests/web/components/TargetDetailDrawer.test.tsx

@@ -85,4 +85,39 @@ describe("TargetDetailDrawer", () => {
     // Just verify rendering doesn't throw
     expect(asFragment()).not.toBeNull();
   });
+
+  test("Drawer 使用响应式默认宽度 CSS 变量", () => {
+    render(<TargetDetailDrawer {...defaultProps} />);
+    const wrapper = document.querySelector<HTMLElement>(".t-drawer__content-wrapper")!;
+    expect(wrapper).not.toBeNull();
+    expect(wrapper.style.width).toBe("var(--target-detail-drawer-width)");
+  });
+
+  test("Drawer 包含业务 className", () => {
+    render(<TargetDetailDrawer {...defaultProps} />);
+    const drawer = document.querySelector(".target-detail-drawer");
+    expect(drawer).not.toBeNull();
+  });
+
+  test("Drawer 启用 sizeDraggable 拖拽", () => {
+    render(<TargetDetailDrawer {...defaultProps} />);
+    const wrapper = document.querySelector<HTMLElement>(".t-drawer__content-wrapper")!;
+    expect(wrapper).not.toBeNull();
+    const dragLine = wrapper.querySelector('[style*="col-resize"]');
+    expect(dragLine).not.toBeNull();
+  });
+
+  test("Drawer 拖拽宽度不写入 localStorage", () => {
+    const keysBefore = window.localStorage.length;
+    render(<TargetDetailDrawer {...defaultProps} />);
+    expect(window.localStorage.length).toBe(keysBefore);
+  });
+
+  test("Drawer sizeDraggable 配置最小拖拽边界", () => {
+    render(<TargetDetailDrawer {...defaultProps} />);
+    const wrapper = document.querySelector<HTMLElement>(".t-drawer__content-wrapper")!;
+    expect(wrapper).not.toBeNull();
+    const dragLine = wrapper.querySelector('[style*="col-resize"]');
+    expect(dragLine).not.toBeNull();
+  });
 });