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/llm/output-expect.test.ts

@@ -2,8 +2,12 @@ import { describe, expect, test } from "bun:test";
 
 import type { LlmCheckObservation } from "../../../../../src/server/checker/runner/llm/types";
 
+import { checkContentRules } from "../../../../../src/server/checker/expect/content";
 import { runExpects } from "../../../../../src/server/checker/runner/llm/expect";
-import { checkOutputRules } from "../../../../../src/server/checker/runner/llm/output";
+
+function checkOutputRules(outputText: null | string, rules: Parameters<typeof checkContentRules>[1]) {
+  return checkContentRules(outputText, rules, { path: "output", phase: "output" });
+}
 
 function makeObservation(overrides?: Partial<LlmCheckObservation>): LlmCheckObservation {
   return {
@@ -72,7 +76,7 @@ describe("LLM runExpects", () => {
   test("全部 expect 通过", () => {
     const observation = makeObservation();
     const result = runExpects(observation, {
-      finishReason: "stop",
+      finishReason: { equals: "stop" },
       output: [{ contains: "OK" }],
       status: [200],
     });
@@ -95,14 +99,14 @@ describe("LLM runExpects", () => {
 
   test("finishReason 不匹配失败", () => {
     const observation = makeObservation();
-    const result = runExpects(observation, { finishReason: "length" });
+    const result = runExpects(observation, { finishReason: { equals: "length" } });
     expect(result.matched).toBe(false);
     expect(result.failure?.phase).toBe("finishReason");
   });
 
   test("rawFinishReason 不匹配失败", () => {
     const observation = makeObservation();
-    const result = runExpects(observation, { rawFinishReason: "end_turn" });
+    const result = runExpects(observation, { rawFinishReason: { equals: "end_turn" } });
     expect(result.matched).toBe(false);
     expect(result.failure?.phase).toBe("rawFinishReason");
   });