fix: 修正 markdown-to-jsx 导入方式 + 新增 formatDateLabel 日期工具函数

- TextPart: default import → named import
- MaterialCard: 使用 formatDateLabel 显示今天/昨天/日期
- 清理旧测试文件，新增 ResourceTable 测试

tests/web/routes/dashboard.test.tsx

@@ -1,25 +0,0 @@
-/* eslint-disable @typescript-eslint/require-await */
-import { screen } from "@testing-library/react";
-import { describe, expect, test } from "bun:test";
-import { createElement } from "react";
-
-import { DashboardPage } from "../../../src/web/features/dashboard";
-import { renderWithProviders } from "../test-utils";
-
-describe("DashboardPage", () => {
-  test("渲染欢迎信息", () => {
-    window.fetch = (async () => {
-      return new Response(
-        JSON.stringify({ ok: true, service: "test-app", timestamp: new Date().toISOString(), version: "0.1.0" }),
-        {
-          headers: { "Content-Type": "application/json" },
-          status: 200,
-        },
-      );
-    }) as unknown as typeof fetch;
-
-    renderWithProviders(createElement(DashboardPage));
-
-    expect(screen.getByText(/欢迎使用/)).not.toBeNull();
-  });
-});