refactor: 统一 expect 断言体系，引入共享 ValueMatcher/ContentRules/KeyValueExpect 模型

- 引入共享 ValueMatcher（equals/contains/regex/exists/empty/gt/gte/lt/lte）
- 引入共享 ContentRules 数组（direct/json/css/xpath 提取器）
- 引入共享 KeyValueExpect（动态键值断言，字面量等价 equals）
- maxDurationMs → durationMs: ValueMatcher（所有 checker）
- match → regex（固定无 flags）
- Ping max* → packetLossPercent/avgLatencyMs/maxLatencyMs（ValueMatcher）
- LLM finishReason/rawFinishReason → ValueMatcher
- DB 新增 result: ContentRules
- TCP banner → ContentRules 数组
- 删除旧模块：operator.ts、validate-operator.ts、duration.ts、body.ts、text.ts、output.ts
- 更新全部 checker schema/validate/expect/execute
- 更新 probe-config.schema.json、probes.example.yaml
- 更新 README.md、DEVELOPMENT.md（含 expect 字段选择规范）
- 同步 10 个 delta specs 到主 specs，归档 change

tests/server/checker/runner/db/validate.test.ts

@@ -49,20 +49,20 @@ describe("validateDbConfig", () => {
     expect(unknownError!.code).toBe("unknown-field");
   });
 
-  test("expect.maxDurationMs 非数字返回错误", () => {
+  test("expect.durationMs 非 matcher 返回错误", () => {
     const result = validateDbConfig({
       defaults: {},
       targets: [
         {
           db: { url: "sqlite://:memory:" },
-          expect: { maxDurationMs: "invalid" },
+          expect: { durationMs: "invalid" },
           id: "test",
           name: "test",
           type: "db",
         },
       ],
     });
-    const durationError = result.find((e) => e.path.includes("expect.maxDurationMs"));
+    const durationError = result.find((e) => e.path.includes("expect.durationMs"));
     expect(durationError).toBeDefined();
     expect(durationError!.code).toBe("invalid-type");
   });
@@ -76,7 +76,7 @@ describe("validateDbConfig", () => {
     });
     const rowCountError = result.find((e) => e.path.includes("expect.rowCount"));
     expect(rowCountError).toBeDefined();
-    expect(rowCountError!.code).toBe("unknown-operator");
+    expect(rowCountError!.code).toBe("unknown-matcher");
   });
 
   test("expect.rows 不是数组返回错误", () => {
@@ -103,13 +103,13 @@ describe("validateDbConfig", () => {
     expect(rowError!.code).toBe("invalid-type");
   });
 
-  test("expect.rows 中 match 正则非法返回错误", () => {
+  test("expect.rows 中 regex 正则非法返回错误", () => {
     const result = validateDbConfig({
       defaults: {},
       targets: [
         {
           db: { url: "sqlite://:memory:" },
-          expect: { rows: [{ name: { match: "[invalid" } }] },
+          expect: { rows: [{ name: { regex: "[invalid" } }] },
           id: "test",
           name: "test",
           type: "db",
@@ -137,7 +137,7 @@ describe("validateDbConfig", () => {
       targets: [
         {
           db: { query: "SELECT 1", url: "sqlite://:memory:" },
-          expect: { maxDurationMs: 5000, rowCount: { gte: 1 }, rows: [{ cnt: { gte: 1 } }] },
+          expect: { durationMs: { lte: 5000 }, rowCount: { gte: 1 }, rows: [{ cnt: { gte: 1 } }] },
           id: "test",
           name: "test",
           type: "db",