feat(kafka): 移除Kafka集成服务

- 删除了KafkaIntegrationService类及其相关逻辑
- 移除了Kafka消息发送和连接测试功能
- 清理了未实现的预留接口方法
- 移除了相关的配置属性获取方法

src/main/java/com/ycwl/basic/integration/kafka/service/KafkaIntegrationService.java

@@ -1,51 +0,0 @@
-package com.ycwl.basic.integration.kafka.service;
-
-import com.ycwl.basic.integration.kafka.config.KafkaIntegrationProperties;
-import com.ycwl.basic.integration.kafka.dto.KafkaMessage;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.kafka.core.KafkaTemplate;
-import org.springframework.stereotype.Service;
-
-@Slf4j
-@Service
-@RequiredArgsConstructor
-@ConditionalOnProperty(name = "kafka.enabled", havingValue = "true")
-public class KafkaIntegrationService {
-
-    private final KafkaTemplate<String, String> kafkaTemplate;
-    private final KafkaIntegrationProperties kafkaProperties;
-
-    /**
-     * 测试Kafka连接
-     */
-    public boolean testConnection() {
-        try {
-            log.info("Testing Kafka connection to: {}", kafkaProperties.getBootstrapServers());
-            
-            // 尝试获取元数据以测试连接
-            var metadata = kafkaTemplate.getProducerFactory().createProducer().partitionsFor("test-topic");
-            log.info("Kafka connection test successful");
-            return true;
-        } catch (Exception e) {
-            log.error("Kafka connection test failed", e);
-            return false;
-        }
-    }
-
-    /**
-     * 发送消息（预留接口，暂不实现具体逻辑）
-     */
-    public void sendMessage(String topic, String key, KafkaMessage<?> message) {
-        log.info("Kafka message sending is not implemented yet. Topic: {}, Key: {}", topic, key);
-        // TODO: 后续实现具体的消息发送逻辑
-    }
-
-    /**
-     * 获取Kafka配置信息
-     */
-    public KafkaIntegrationProperties getKafkaProperties() {
-        return kafkaProperties;
-    }
-}