feat: 重构配置校验为 TypeBox + Ajv + semantic validator，严格禁止未知字段

- 新增 config-contract 模块（TypeBox fragments、Ajv 契约校验、ConfigValidationIssue）
- CheckerDefinition 扩展为含 configKey、schemas、validate 的完整插件接口
- HTTP/Command 各自维护 contract.ts + validate.ts，校验从 resolve 中分离
- resolve 不再承担校验，只做默认值合并和路径/单位解析
- config-loader 流程: unknown → RawProbeConfig → ValidatedProbeConfig → ResolvedConfig
- 导出 probe-config.schema.json，新增 schema/schema:check 脚本
- 更新 DEVELOPMENT.md 新增 1.7 开发新 Checker 完整指引
- 同步更新 4 个 main specs（probe-config、command-checker、expect-body-checkers、checker-runner-abstraction）

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

@@ -69,6 +69,13 @@ describe("applyOperator", () => {
     expect(applyOperator(true, { equals: true })).toBe(true);
   });
 
+  test("equals 支持 JSON 对象和数组", () => {
+    expect(applyOperator({ status: "ok" }, { equals: { status: "ok" } })).toBe(true);
+    expect(applyOperator({ status: "ok" }, { equals: { status: "fail" } })).toBe(false);
+    expect(applyOperator(["a", "b"], { equals: ["a", "b"] })).toBe(true);
+    expect(applyOperator(["a", "b"], { equals: ["b", "a"] })).toBe(false);
+  });
+
   test("contains 操作符", () => {
     expect(applyOperator("hello world", { contains: "hello" })).toBe(true);
     expect(applyOperator("hello world", { contains: "missing" })).toBe(false);