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

src/server/checker/runner/udp/schema.ts

@@ -2,7 +2,7 @@ import { Type } from "@sinclair/typebox";
 
 import type { CheckerSchemas } from "../types";
 
-import { createPureOperatorSchema, createTextRulesSchema, sizeSchema } from "../../schema/fragments";
+import { createContentRulesSchema, createValueMatcherSchema, sizeSchema } from "../../schema/fragments";
 
 export const udpCheckerSchemas: CheckerSchemas = {
   config: Type.Object(
@@ -26,12 +26,12 @@ export const udpCheckerSchemas: CheckerSchemas = {
   ),
   expect: Type.Object(
     {
-      maxDurationMs: Type.Optional(Type.Number({ minimum: 0 })),
+      durationMs: Type.Optional(createValueMatcherSchema()),
       responded: Type.Optional(Type.Boolean()),
-      response: Type.Optional(createTextRulesSchema()),
-      responseSize: Type.Optional(createPureOperatorSchema()),
-      sourceHost: Type.Optional(createPureOperatorSchema()),
-      sourcePort: Type.Optional(createPureOperatorSchema()),
+      response: Type.Optional(createContentRulesSchema()),
+      responseSize: Type.Optional(createValueMatcherSchema()),
+      sourceHost: Type.Optional(createValueMatcherSchema()),
+      sourcePort: Type.Optional(createValueMatcherSchema()),
     },
     { additionalProperties: false },
   ),