feat: 重构配置生命周期为 Authoring/Normalized/Resolved 三层

将变量替换和 expect 简写展开统一放入 Normalized 阶段，
运行时 AJV 使用 Normalized schema，导出 schema 面向 Authoring Config。

主要变更：
- 新增 normalizer.ts 实现 normalizeAuthoringConfig()
- 拆分 Authoring/Normalized 双 schema，checker 接口支持 authoring/normalized 片段
- config-loader 流程：normalize → Normalized AJV → semantic → resolve
- validator 兼容层自动分派 raw/normalized expect 形态
- 删除 rawExpect，store.expect 列写入 null
- Authoring schema 对 integer/boolean/enum 字段接受变量引用
- 修复 DB/HTTP validate 入口守卫和 LLM options integer 变量引用
- 优化 compact() 避免 undefined 覆盖隐患
- 移除 content.ts 恒为 true 的前置条件
- 同步 5 个主规范并归档 change

tests/server/checker/store.test.ts

@@ -39,7 +39,6 @@ const httpTarget: ResolvedHttpTarget = {
   id: "test-http",
   intervalMs: 30000,
   name: "test-http",
-  rawExpect: { body: [{ contains: "ok" }], durationMs: 3000 },
   timeoutMs: 10000,
   type: "http",
 };
@@ -107,7 +106,7 @@ describe("ProbeStore", () => {
     expect(config.maxRedirects).toBe(0);
     expect(t.interval_ms).toBe(30000);
     expect(t.timeout_ms).toBe(10000);
-    expect(JSON.parse(t.expect!)).toEqual({ body: [{ contains: "ok" }], durationMs: 3000 });
+    expect(t.expect).toBeNull();
   });
 
   test("cmd target 字段正确", () => {