feat: 将 demo 项目转化为 HTTP 拨测监控工具

新增 YAML 配置解析（Bun 内置 YAML）、SQLite 数据存储（bun:sqlite）、按 interval 分组并发拨测引擎、REST API（/api/summary、/api/targets、/api/targets/:id/history、/api/targets/:id/trend）、React 前端 Dashboard（统计卡片、目标表格、可展开详情面板、recharts 趋势图）。CLI 简化为仅接受配置文件路径。移除 /api/demo 路由和相关 demo 代码。保留 /health、静态资源服务和 SPA fallback。

tests/server/checker/engine.test.ts

@@ -0,0 +1,92 @@
+import { afterAll, beforeAll, describe, expect, test } from "bun:test";
+import { ProbeStore } from "../../../src/server/checker/store";
+import { ProbeEngine } from "../../../src/server/checker/engine";
+import type { ResolvedTarget } from "../../../src/server/checker/types";
+import { mkdir, rm } from "node:fs/promises";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+
+describe("ProbeEngine", () => {
+  let tempDir: string;
+  let store: ProbeStore;
+
+  const target: ResolvedTarget = {
+    name: "httpbin",
+    url: "https://httpbin.org/get",
+    method: "GET",
+    headers: {},
+    intervalMs: 60000,
+    timeoutMs: 10000,
+  };
+
+  beforeAll(async () => {
+    tempDir = join(tmpdir(), `gc-engine-test-${Date.now()}`);
+    await mkdir(tempDir, { recursive: true });
+    store = new ProbeStore(join(tempDir, "test.db"));
+    store.syncTargets([target]);
+  });
+
+  afterAll(async () => {
+    store.close();
+    await rm(tempDir, { recursive: true, force: true });
+  });
+
+  test("groupByInterval 分组逻辑", () => {
+    const targets: ResolvedTarget[] = [
+      { name: "a", url: "http://a.com", method: "GET", headers: {}, intervalMs: 30000, timeoutMs: 10000 },
+      { name: "b", url: "http://b.com", method: "GET", headers: {}, intervalMs: 30000, timeoutMs: 10000 },
+      { name: "c", url: "http://c.com", method: "GET", headers: {}, intervalMs: 60000, timeoutMs: 10000 },
+    ];
+
+    const engine = new ProbeEngine(store, targets);
+    engine.start();
+    engine.stop();
+
+    // 只要能启动和停止不出错就行
+    expect(true).toBe(true);
+  });
+
+  test("engine start/stop 不抛错", () => {
+    const engine = new ProbeEngine(store, [target]);
+    engine.start();
+    engine.stop();
+    expect(true).toBe(true);
+  });
+
+  test("单次拨测写入数据库", async () => {
+    const engine = new ProbeEngine(store, [target]);
+    // 手动调用 probeGroup 不启动 timer
+    const probeGroup = (engine as unknown as { probeGroup: (t: ResolvedTarget[]) => Promise<void> }).probeGroup.bind(engine);
+    await probeGroup([target]);
+
+    const dbTargets = store.getTargets();
+    const latest = store.getLatestCheck(dbTargets[0]!.id);
+    expect(latest).not.toBeNull();
+    expect(latest!.success === 1 || latest!.success === 0).toBe(true);
+  });
+
+  test("单目标失败隔离", async () => {
+    const badTarget: ResolvedTarget = {
+      name: "bad-target",
+      url: "http://127.0.0.1:1/impossible",
+      method: "GET",
+      headers: {},
+      intervalMs: 60000,
+      timeoutMs: 2000,
+    };
+
+    store.syncTargets([target, badTarget]);
+
+    const engine = new ProbeEngine(store, [target, badTarget]);
+    const probeGroup = (engine as unknown as { probeGroup: (t: ResolvedTarget[]) => Promise<void> }).probeGroup.bind(engine);
+    await probeGroup([target, badTarget]);
+
+    const dbTargets = store.getTargets();
+    const goodResult = store.getLatestCheck(dbTargets.find((t) => t.name === "httpbin")!.id);
+    const badResult = store.getLatestCheck(dbTargets.find((t) => t.name === "bad-target")!.id);
+
+    expect(goodResult).not.toBeNull();
+    expect(badResult).not.toBeNull();
+    expect(badResult!.success).toBe(0);
+  });
+});