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/runner/llm/schema-validate-resolve.test.ts

@@ -214,7 +214,7 @@ describe("LlmChecker validate", () => {
       defaults: {},
       targets: [makeRawTarget({ expect: { output: [{ contains: "y", json: { path: "$.status" } }] } })],
     });
-    expect(issues.some((i) => i.code === "invalid-content-rule")).toBe(true);
+    expect(issues.some((i) => i.code === "invalid-content-expectation")).toBe(true);
   });
 
   test("expect.output regex ReDoS 报错", () => {
@@ -284,6 +284,44 @@ describe("LlmChecker resolve", () => {
     expect(resolved.group).toBe("default");
     expect(resolved.intervalMs).toBe(30000);
     expect(resolved.timeoutMs).toBe(10000);
+    expect(resolved.rawExpect).toBeUndefined();
+    expect(resolved.expect).toEqual({ status: [200] });
+  });
+
+  test("stream mode 未配置 expect.stream 时不物化 completed", () => {
+    const raw = makeRawTarget({
+      expect: { output: [{ contains: "OK" }] },
+      llm: {
+        mode: "stream",
+        model: "gpt-4o-mini",
+        prompt: "Say OK",
+        provider: "openai",
+        url: "https://api.openai.com/v1",
+      },
+    });
+
+    const resolved = asLlm(checker.resolve(raw, makeResolveContext()));
+
+    expect(resolved.rawExpect).toEqual({ output: [{ contains: "OK" }] });
+    expect(resolved.expect?.stream).toBeUndefined();
+  });
+
+  test("配置 expect.stream 但省略 completed 时默认 true", () => {
+    const raw = makeRawTarget({
+      expect: { stream: { firstTokenMs: 100 } },
+      llm: {
+        mode: "stream",
+        model: "gpt-4o-mini",
+        prompt: "Say OK",
+        provider: "openai",
+        url: "https://api.openai.com/v1",
+      },
+    });
+
+    const resolved = asLlm(checker.resolve(raw, makeResolveContext()));
+
+    expect(resolved.rawExpect).toEqual({ stream: { firstTokenMs: 100 } });
+    expect(resolved.expect?.stream).toEqual({ completed: true, firstTokenMs: { equals: 100 } });
   });
 
   test("defaults.llm 与 target.llm 浅合并", () => {