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/icmp/expect.test.ts

@@ -16,22 +16,22 @@ describe("ping expect", () => {
   });
 
   test("packetLoss 通过和失败", () => {
-    expect(checkPacketLoss(0, 10).matched).toBe(true);
-    const result = checkPacketLoss(33, 10);
+    expect(checkPacketLoss(0, { lte: 10 }).matched).toBe(true);
+    const result = checkPacketLoss(33, { lte: 10 });
     expect(result.matched).toBe(false);
     expect(result.failure?.phase).toBe("packetLoss");
   });
 
   test("avgLatency 通过和失败", () => {
-    expect(checkAvgLatency(12, 200).matched).toBe(true);
-    const result = checkAvgLatency(156, 100);
+    expect(checkAvgLatency(12, { lte: 200 }).matched).toBe(true);
+    const result = checkAvgLatency(156, { lte: 100 });
     expect(result.matched).toBe(false);
     expect(result.failure?.phase).toBe("avgLatency");
   });
 
   test("maxLatency 通过和失败", () => {
-    expect(checkMaxLatency(340, 500).matched).toBe(true);
-    const result = checkMaxLatency(340, 200);
+    expect(checkMaxLatency(340, { lte: 500 }).matched).toBe(true);
+    const result = checkMaxLatency(340, { lte: 200 });
     expect(result.matched).toBe(false);
     expect(result.failure?.phase).toBe("maxLatency");
   });