feat: 重构为多类型 checker 通用框架，支持 HTTP 与命令检查

- 引入 typed target 判别联合，支持 http 与 command 两种 checker
- expect 重构为有序规则数组，按配置顺序快速失败并生成结构化 failure
- 新增 command runner，支持 exec + args 本地命令执行
- 引入全局并发限制 maxConcurrentChecks 和 size 解析 (KB/MB/GB)
- HTTP/command 各自独立 expect pipeline，应用领域默认成功语义
- SQLite schema、API、Dashboard 全链路调整为 checker 通用契约
- 补充完整测试覆盖（192 tests），更新 README 与示例配置

tests/server/app.test.ts

@@ -26,18 +26,27 @@ describe("API 路由", () => {
     store = new ProbeStore(join(tempDir, "test.db"));
     store.syncTargets([
       {
+        type: "http",
         name: "test-a",
-        url: "http://a.com",
-        method: "GET",
-        headers: {},
+        http: {
+          url: "http://a.com",
+          method: "GET",
+          headers: {},
+          maxBodyBytes: 104857600,
+        },
         intervalMs: 30000,
         timeoutMs: 10000,
       },
       {
+        type: "command",
         name: "test-b",
-        url: "http://b.com",
-        method: "POST",
-        headers: {},
+        command: {
+          exec: "echo",
+          args: ["hello"],
+          cwd: "/tmp",
+          env: {},
+          maxOutputBytes: 104857600,
+        },
         intervalMs: 60000,
         timeoutMs: 5000,
       },
@@ -48,19 +57,26 @@ describe("API 路由", () => {
       targetId: targets[0]!.id,
       timestamp: "2025-01-01T00:00:00.000Z",
       success: true,
-      statusCode: 200,
-      latencyMs: 150,
-      error: null,
       matched: true,
+      durationMs: 150,
+      statusDetail: "200 OK",
+      failure: null,
     });
     store.insertCheckResult({
       targetId: targets[0]!.id,
       timestamp: "2025-01-01T00:00:30.000Z",
       success: false,
-      statusCode: null,
-      latencyMs: null,
-      error: "timeout",
       matched: false,
+      durationMs: null,
+      statusDetail: null,
+      failure: {
+        kind: "error",
+        phase: "status",
+        path: "$.status",
+        expected: 200,
+        actual: 500,
+        message: "状态码不匹配",
+      },
     });
 
     fetchHandler = createFetchHandler({ mode: "test", staticAssets, store });
@@ -88,6 +104,7 @@ describe("API 路由", () => {
     expect(body.up).toBeGreaterThanOrEqual(0);
     expect(body.down).toBeGreaterThanOrEqual(0);
     expect(body.up + body.down).toBe(2);
+    expect(body.avgDurationMs).toBeDefined();
   });
 
   test("/api/targets 返回目标列表", async () => {
@@ -96,12 +113,23 @@ describe("API 路由", () => {
 
     expect(response.status).toBe(200);
     expect(body).toHaveLength(2);
-    expect(body[0]!.name).toBe("test-a");
-    expect(body[0]!.latestCheck).not.toBeNull();
-    expect(body[0]!.latestCheck!.success).toBe(false);
-    expect(body[0]!.sparkline).toBeDefined();
-    expect(Array.isArray(body[0]!.sparkline)).toBe(true);
-    expect(body[1]!.latestCheck).toBeNull();
+
+    const tA = body.find((t) => t.name === "test-a")!;
+    expect(tA.type).toBe("http");
+    expect(tA.target).toBe("http://a.com");
+    expect(tA.latestCheck).not.toBeNull();
+    expect(tA.latestCheck!.success).toBe(false);
+    expect(tA.latestCheck!.matched).toBe(false);
+    expect(tA.latestCheck!.failure).not.toBeNull();
+    expect(tA.sparkline).toBeDefined();
+    expect(Array.isArray(tA.sparkline)).toBe(true);
+    expect(tA.stats.avgDurationMs).toBeDefined();
+    expect(tA.stats.p99DurationMs).toBeDefined();
+
+    const tB = body.find((t) => t.name === "test-b")!;
+    expect(tB.type).toBe("command");
+    expect(tB.target).toBe("exec echo hello");
+    expect(tB.latestCheck).toBeNull();
   });
 
   test("/api/targets/:id/history 返回历史记录", async () => {
@@ -111,6 +139,8 @@ describe("API 路由", () => {
 
     expect(response.status).toBe(200);
     expect(body).toHaveLength(2);
+    expect(body[0].failure).not.toBeNull();
+    expect(body[0].failure.kind).toBe("error");
   });
 
   test("/api/targets/:id/history 支持 limit 参数", async () => {