refactor: expect 类型模型重构，Raw/Resolved 双层分离与断言基础设施内聚

- 重命名 ContentRules→ContentExpectations, KeyValueExpect→KeyedExpectations
- 新增 Raw/Resolved 双层模型：resolve 阶段物化为执行计划，store 持久化 Raw 快照
- HTTP body 按需读取：status/headers 失败或无 body expectation 时不读取 body
- 新增 displayValueExpectation() 解包 failure.expected 用户可读展示
- 修复 checkEarlyTimeout 独立 lte/lt 检查，修复 KeyedExpectations JSON Schema
- 新增 expect/value.ts(resolve/check/display)、keyed.ts、content.ts、headers.ts、status.ts
- 删除旧 normalize.ts/matcher.ts/validate-matcher.ts/key-value.ts
- 更新 DEVELOPMENT.md：expect 五层管线表、displayValueExpectation、1.7↔1.10 交叉引用
- 同步 13 个 main specs，归档 refactor-expect-type-model 变更（62/62 tasks）

tests/server/checker/config-contract/validate.test.ts

@@ -84,6 +84,33 @@ describe("config contract", () => {
     expect(validate(target({ equals: { status: "ok" } }))).toBe(true);
   });
 
+  test("导出 schema 拒绝 KeyedExpectations 的数组和对象简写", () => {
+    const ajv = new Ajv({
+      allErrors: true,
+      coerceTypes: false,
+      removeAdditional: false,
+      strict: true,
+      useDefaults: false,
+    });
+    const validate = ajv.compile(createProbeConfigJsonSchema(createDefaultCheckerRegistry()));
+    const target = (headerValue: unknown) => ({
+      targets: [
+        {
+          expect: { headers: { "x-test": headerValue } },
+          http: { url: "https://example.com" },
+          id: "api",
+          type: "http",
+        },
+      ],
+    });
+
+    expect(validate(target("ok"))).toBe(true);
+    expect(validate(target({ contains: "ok" }))).toBe(true);
+    expect(validate(target(["ok"]))).toBe(false);
+    expect(validate(target({ nested: "ok" }))).toBe(false);
+    expect(validate(target({ equals: { nested: "ok" } }))).toBe(true);
+  });
+
   test("Ajv 错误转换为中文结构化 issue", () => {
     const result = validateProbeConfigContract(
       {