fix(mqtt): 增强MQTT消息收发测试的消息体打印

- 单独打印发送的消息体
- 单独打印接收的消息体
- 打印预期消息体用于对比
- 将消息不匹配从INFO改为WARN级别
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

AuxiliaryTool/ScriptTool/ServiceSelfInspection/check_server_health.sh

@@ -1599,12 +1599,13 @@ test_mqtt_connection() {
 
         # 步骤2: 发送测试消息
         log INFO "[MQTT] 步骤2/3: 发送测试消息到主题: $test_topic"
+        log INFO "[MQTT] 发送消息体: [$test_message]"
         local pub_output
         pub_output="$(docker exec "$actual_container" mosquitto_pub -h localhost -p "$mqtt_port" -t "$test_topic" -m "$test_message" 2>&1)"
         local pub_exit_code=$?
 
         if [[ $pub_exit_code -eq 0 ]]; then
-          log SUCCESS "[MQTT] 消息发送成功: $test_message"
+          log SUCCESS "[MQTT] 消息发送成功"
           local pub_success=1
         else
           log ERROR "[MQTT] 消息发送失败: $pub_output"
@@ -1623,11 +1624,15 @@ test_mqtt_connection() {
           # 清理临时文件
           docker exec "$actual_container" rm -f "$sub_output_file" 2>/dev/null || true
 
+          # 打印接收到的原始消息体
+          log INFO "[MQTT] 接收消息体: [$received_message]"
+          log INFO "[MQTT] 预期消息体: [$test_message]"
+
           if [[ "$received_message" =~ "$test_message" ]]; then
             log SUCCESS "[MQTT] 消息接收验证成功"
             local recv_success=1
           else
-            log INFO "[MQTT] 消息接收: $received_message (订阅通道正常)"
+            log WARN "[MQTT] 消息内容不匹配，但订阅通道正常"
             local recv_success=1
           fi
         else