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）

src/server/checker/expect/normalize.ts

@@ -1,22 +0,0 @@
-import type { ValueMatcherPrimitive } from "./types";
-
-import { isValueMatcherObject } from "./matcher";
-
-export function isValueMatcherPrimitive(value: unknown): value is ValueMatcherPrimitive {
-  return value === null || typeof value === "string" || typeof value === "number" || typeof value === "boolean";
-}
-
-export function normalizeExpectMatchers(expect: Record<string, unknown>, keys: string[]): void {
-  for (const key of keys) {
-    if (key in expect) {
-      expect[key] = normalizeValueMatcher(expect[key]);
-    }
-  }
-}
-
-export function normalizeValueMatcher(value: unknown): unknown {
-  if (value === undefined) return undefined;
-  if (isValueMatcherObject(value)) return value;
-  if (isValueMatcherPrimitive(value)) return { equals: value };
-  return value;
-}