refactor: 引入 Checker 统一接口与 Runner 抽象机制

定义 Checker 接口（resolve/execute/serialize）和 CheckerRegistry
注册中心，消除 engine/config-loader/store 中硬编码类型分支。
按 checker 类型分子包（runner/http/、runner/command/），提取
共享 expect 到 runner/shared/。超时控制通过引擎注入 AbortSignal。
CheckFailure.phase 从联合类型改为 string。配置校验下沉到各
Checker.resolve() 内部。

新增 checker-runner-abstraction spec，更新 DEVELOPMENT.md。

tests/server/checker/runner/shared/operator.test.ts

@@ -0,0 +1,141 @@
+import { describe, expect, test } from "bun:test";
+import { applyOperator, checkExpectValue, evaluateJsonPath } from "../../../../../src/server/checker/runner/shared/operator";
+
+describe("evaluateJsonPath", () => {
+  const obj = {
+    status: "ok",
+    code: 0,
+    active: true,
+    error: null,
+    data: {
+      count: 42,
+      items: [{ name: "a" }, { name: "b" }],
+      nested: { deep: "value" },
+    },
+    emptyObj: {},
+    emptyArr: [],
+  };
+
+  test("简单字段访问", () => {
+    expect(evaluateJsonPath(obj, "$.status")).toBe("ok");
+    expect(evaluateJsonPath(obj, "$.code")).toBe(0);
+    expect(evaluateJsonPath(obj, "$.active")).toBe(true);
+    expect(evaluateJsonPath(obj, "$.error")).toBeNull();
+  });
+
+  test("嵌套对象访问", () => {
+    expect(evaluateJsonPath(obj, "$.data.count")).toBe(42);
+    expect(evaluateJsonPath(obj, "$.data.nested.deep")).toBe("value");
+  });
+
+  test("数组索引访问", () => {
+    expect(evaluateJsonPath(obj, "$.data.items[0].name")).toBe("a");
+    expect(evaluateJsonPath(obj, "$.data.items[1].name")).toBe("b");
+  });
+
+  test("路径不存在返回 undefined", () => {
+    expect(evaluateJsonPath(obj, "$.notExist")).toBeUndefined();
+    expect(evaluateJsonPath(obj, "$.data.notExist")).toBeUndefined();
+    expect(evaluateJsonPath(obj, "$.data.items[99]")).toBeUndefined();
+  });
+
+  test("空对象和空数组", () => {
+    expect(evaluateJsonPath(obj, "$.emptyObj")).toEqual({});
+    expect(evaluateJsonPath(obj, "$.emptyArr")).toEqual([]);
+  });
+
+  test("非 $ 开头路径返回 undefined", () => {
+    expect(evaluateJsonPath(obj, "status")).toBeUndefined();
+    expect(evaluateJsonPath(obj, ".status")).toBeUndefined();
+  });
+
+  test("null 对象上访问", () => {
+    expect(evaluateJsonPath(null, "$.any")).toBeUndefined();
+  });
+});
+
+describe("applyOperator", () => {
+  test("equals 操作符", () => {
+    expect(applyOperator("ok", { equals: "ok" })).toBe(true);
+    expect(applyOperator("ok", { equals: "error" })).toBe(false);
+    expect(applyOperator(42, { equals: 42 })).toBe(true);
+    expect(applyOperator(42, { equals: 41 })).toBe(false);
+    expect(applyOperator(null, { equals: null })).toBe(true);
+    expect(applyOperator(true, { equals: true })).toBe(true);
+  });
+
+  test("contains 操作符", () => {
+    expect(applyOperator("hello world", { contains: "hello" })).toBe(true);
+    expect(applyOperator("hello world", { contains: "missing" })).toBe(false);
+    expect(applyOperator(12345, { contains: "23" })).toBe(true);
+  });
+
+  test("match 操作符", () => {
+    expect(applyOperator("v2.1.0", { match: "\\d+\\.\\d+\\.\\d+" })).toBe(true);
+    expect(applyOperator("v2.1", { match: "\\d+\\.\\d+\\.\\d+" })).toBe(false);
+    expect(applyOperator("abc123", { match: "^\\w+\\d+$" })).toBe(true);
+  });
+
+  test("empty 操作符", () => {
+    expect(applyOperator("", { empty: true })).toBe(true);
+    expect(applyOperator(null, { empty: true })).toBe(true);
+    expect(applyOperator(undefined, { empty: true })).toBe(true);
+    expect(applyOperator([], { empty: true })).toBe(true);
+    expect(applyOperator({}, { empty: true })).toBe(true);
+    expect(applyOperator("ok", { empty: true })).toBe(false);
+    expect(applyOperator([1, 2], { empty: false })).toBe(true);
+    expect(applyOperator([], { empty: false })).toBe(false);
+  });
+
+  test("exists 操作符", () => {
+    expect(applyOperator("ok", { exists: true })).toBe(true);
+    expect(applyOperator(null, { exists: true })).toBe(true);
+    expect(applyOperator(undefined, { exists: true })).toBe(false);
+    expect(applyOperator(undefined, { exists: false })).toBe(true);
+    expect(applyOperator("ok", { exists: false })).toBe(false);
+  });
+
+  test("gte 操作符", () => {
+    expect(applyOperator(10, { gte: 5 })).toBe(true);
+    expect(applyOperator(5, { gte: 5 })).toBe(true);
+    expect(applyOperator(3, { gte: 5 })).toBe(false);
+    expect(applyOperator("10", { gte: 5 })).toBe(true);
+  });
+
+  test("lte 操作符", () => {
+    expect(applyOperator(3, { lte: 5 })).toBe(true);
+    expect(applyOperator(5, { lte: 5 })).toBe(true);
+    expect(applyOperator(10, { lte: 5 })).toBe(false);
+  });
+
+  test("gt 操作符", () => {
+    expect(applyOperator(10, { gt: 5 })).toBe(true);
+    expect(applyOperator(5, { gt: 5 })).toBe(false);
+  });
+
+  test("lt 操作符", () => {
+    expect(applyOperator(3, { lt: 5 })).toBe(true);
+    expect(applyOperator(5, { lt: 5 })).toBe(false);
+  });
+
+  test("多操作符 AND 组合", () => {
+    expect(applyOperator(7, { gte: 5, lte: 10 })).toBe(true);
+    expect(applyOperator(3, { gte: 5, lte: 10 })).toBe(false);
+    expect(applyOperator(15, { gte: 5, lte: 10 })).toBe(false);
+  });
+});
+
+describe("checkExpectValue", () => {
+  test("原始值直接比较", () => {
+    expect(checkExpectValue("ok", "ok")).toBe(true);
+    expect(checkExpectValue("ok", "error")).toBe(false);
+    expect(checkExpectValue(42, 42)).toBe(true);
+    expect(checkExpectValue(null, null)).toBe(true);
+  });
+
+  test("对象作为操作符", () => {
+    expect(checkExpectValue(42, { gte: 10 })).toBe(true);
+    expect(checkExpectValue(42, { gte: 100 })).toBe(false);
+    expect(checkExpectValue("hello", { contains: "ell" })).toBe(true);
+  });
+});