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/checker/command-runner.test.ts

@@ -0,0 +1,131 @@
+import { describe, expect, test } from "bun:test";
+import { runCommandCheck } from "../../../src/server/checker/command-runner";
+import type { ResolvedCommandTarget } from "../../../src/server/checker/types";
+
+function makeTarget(
+  command: Partial<ResolvedCommandTarget["command"]>,
+  overrides?: Partial<ResolvedCommandTarget>,
+): ResolvedCommandTarget {
+  return {
+    type: "command",
+    name: "test-cmd",
+    command: {
+      exec: "echo",
+      args: ["hello"],
+      cwd: "/tmp",
+      env: {},
+      maxOutputBytes: 1024 * 1024,
+      ...command,
+    },
+    intervalMs: 60000,
+    timeoutMs: 5000,
+    ...overrides,
+  };
+}
+
+describe("runCommandCheck", () => {
+  test("exitCode=0 成功", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "true", args: [] }));
+    expect(result.success).toBe(true);
+    expect(result.matched).toBe(true);
+    expect(result.statusDetail).toBe("exitCode=0");
+    expect(result.failure).toBeNull();
+  });
+
+  test("exitCode=1 不匹配默认 [0]", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "false", args: [] }));
+    expect(result.success).toBe(false);
+    expect(result.matched).toBe(false);
+    expect(result.statusDetail).toBe("exitCode=1");
+    expect(result.failure).not.toBeNull();
+    expect(result.failure!.phase).toBe("exitCode");
+  });
+
+  test("exitCode=1 匹配自定义 [1]", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "false", args: [] }, { expect: { exitCode: [1] } }));
+    expect(result.success).toBe(true);
+    expect(result.matched).toBe(true);
+    expect(result.statusDetail).toBe("exitCode=1");
+  });
+
+  test("命令不存在返回 spawn 错误", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "/nonexistent/command/xyz" }));
+    expect(result.success).toBe(false);
+    expect(result.failure).not.toBeNull();
+    expect(result.failure!.phase).toBe("exitCode");
+    expect(result.failure!.message).toBeTruthy();
+  });
+
+  test("超时返回错误", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "sleep", args: ["10"] }, { timeoutMs: 100 }));
+    expect(result.success).toBe(false);
+    expect(result.failure).not.toBeNull();
+    expect(result.failure!.message).toContain("超时");
+  });
+
+  test("stdout 输出捕获", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "echo", args: ["hello world"] }));
+    expect(result.success).toBe(true);
+  });
+
+  test("stdout 匹配 expect", async () => {
+    const result = await runCommandCheck(
+      makeTarget({ exec: "echo", args: ["hello"] }, { expect: { stdout: [{ contains: "hello" }] } }),
+    );
+    expect(result.success).toBe(true);
+    expect(result.matched).toBe(true);
+  });
+
+  test("stdout 不匹配 expect", async () => {
+    const result = await runCommandCheck(
+      makeTarget({ exec: "echo", args: ["hello"] }, { expect: { stdout: [{ contains: "nonexistent" }] } }),
+    );
+    expect(result.success).toBe(false);
+    expect(result.failure!.phase).toBe("stdout");
+  });
+
+  test("stderr 匹配 expect", async () => {
+    const result = await runCommandCheck(
+      makeTarget({ exec: "bash", args: ["-c", "echo error >&2"] }, { expect: { stderr: [{ contains: "error" }] } }),
+    );
+    expect(result.success).toBe(true);
+    expect(result.matched).toBe(true);
+  });
+
+  test("输出超过 maxOutputBytes", async () => {
+    const result = await runCommandCheck(
+      makeTarget({
+        exec: "bash",
+        args: ["-c", "yes | head -1000"],
+        maxOutputBytes: 10,
+      }),
+    );
+    expect(result.success).toBe(false);
+    expect(result.failure).not.toBeNull();
+    expect(result.failure!.message).toContain("超过限制");
+  });
+
+  test("durationMs 非空", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "true", args: [] }));
+    expect(result.durationMs).not.toBeNull();
+    expect(result.durationMs!).toBeGreaterThanOrEqual(0);
+  });
+
+  test("ls 命令执行成功", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "ls", args: ["/tmp"] }));
+    expect(result.success).toBe(true);
+    expect(result.statusDetail).toBe("exitCode=0");
+  });
+
+  test("不使用 shell，通配符不被展开", async () => {
+    const result = await runCommandCheck(
+      makeTarget({ exec: "echo", args: ["*"] }, { expect: { stdout: [{ contains: "*" }] } }),
+    );
+    expect(result.success).toBe(true);
+  });
+
+  test("不提供 stdin，等待输入的命令会阻塞超时", async () => {
+    const result = await runCommandCheck(makeTarget({ exec: "bash", args: ["-c", "read line"] }, { timeoutMs: 500 }));
+    expect(result.success).toBe(false);
+  });
+});