test: 重构测试体系 — 建立组件测试层、补充后端测试、清理低质量测试

- 新增 jsdom + @testing-library/react 组件测试环境
- 新增 12 个组件测试，覆盖所有前端组件
- 补充后端 middleware 和 helpers 单元测试
- 删除伪测试 use-target-detail-logic.test.ts
- 精简过度枚举的 color-threshold.test.ts
- 新增 bunfig.toml 配置测试 preload
- 更新 DEVELOPMENT.md 测试章节
- 安装 @types/jsdom 修复类型声明

tests/web/components/TargetBoard.test.tsx

@@ -0,0 +1,55 @@
+import "../../../tests/web/test-utils";
+import { render } from "@testing-library/react";
+import { describe, expect, test, vi } from "bun:test";
+
+import type { TargetStatus } from "../../../src/shared/api";
+
+import { TargetBoard } from "../../../src/web/components/TargetBoard";
+
+// Mock useMeta hook
+void vi.mock("../../../src/web/hooks/use-queries", () => ({
+  useMeta: () => ({
+    data: { checkerTypes: ["http", "cmd"] },
+  }),
+}));
+
+describe("TargetBoard", () => {
+  const onTargetClick = vi.fn();
+
+  const targets: TargetStatus[] = [
+    {
+      currentStreak: null,
+      group: "default",
+      id: 1,
+      interval: "30s",
+      latestCheck: null,
+      name: "target-1",
+      recentSamples: [],
+      stats: { availability: 100, downChecks: 0, totalChecks: 0, upChecks: 0 },
+      target: "https://example.com",
+      type: "http",
+    },
+    {
+      currentStreak: null,
+      group: "production",
+      id: 2,
+      interval: "30s",
+      latestCheck: null,
+      name: "target-2",
+      recentSamples: [],
+      stats: { availability: 100, downChecks: 0, totalChecks: 0, upChecks: 0 },
+      target: "https://example.org",
+      type: "http",
+    },
+  ];
+
+  test("有 targets 时不崩溃", () => {
+    const { container } = render(<TargetBoard onTargetClick={onTargetClick} targets={targets} />);
+    expect(container.firstChild).not.toBeNull();
+  });
+
+  test("空 targets 列表不崩溃", () => {
+    const { container } = render(<TargetBoard onTargetClick={onTargetClick} targets={[]} />);
+    expect(container.firstChild).not.toBeNull();
+  });
+});