feat: 交叉验证 AI vs LAMP（#15，一致确认/不一致升级会诊）

server-go/internal/service/cross_validate.go

@@ -0,0 +1,34 @@
+package service
+
+// CrossValidate 交叉验证：AI 检测结果 vs LAMP 检测结果（规格书：一致→确认诊断；不一致→升级专家会诊）
+func CrossValidate(aiClass, lampResult string, lampDiseases []string) (bool, string) {
+	switch {
+	case lampResult == "invalid":
+		return false, "LAMP 判读无效，建议复检或专家会诊"
+	case aiClass == "":
+		return false, "未找到关联巡检记录，暂无法交叉验证"
+	case aiClass == "sick" && lampResult == "positive":
+		return true, "AI 检出异常与 LAMP 阳性一致，确认诊断"
+	case aiClass == "healthy" && lampResult == "negative":
+		return true, "AI 未见异常与 LAMP 阴性一致"
+	case aiClass == "sick" && lampResult == "negative":
+		return false, "AI 检出异常但 LAMP 阴性，建议专家会诊"
+	case aiClass == "healthy" && lampResult == "positive":
+		return false, "AI 未见异常但 LAMP 阳性，建议专家会诊"
+	default:
+		return false, "交叉验证结果待确认"
+	}
+}
+
+// AIClassFromDetections 从巡检检测结果归纳 AI 结论（任一非 healthy 视为 sick）
+func AIClassFromDetections(detections []AIDetection) string {
+	if len(detections) == 0 {
+		return ""
+	}
+	for _, d := range detections {
+		if d.ClassName != "healthy" {
+			return "sick"
+		}
+	}
+	return "healthy"
+}