fix(vsp): 修复 RestTemplate 发送空 JSON body 的问题

VspNotifyClientImpl.executeWithRetry 传裸 POJO 给 postForObject，
RestTemplate 默认 converter 顺序下可能选用 FormHttpMessageConverter
导致序列化为空 {}。改为 HttpEntity 显式设置 Content-Type: application/json，
确保使用 Jackson 序列化。

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

viewsh-module-ops/viewsh-module-ops-biz/src/main/java/com/viewsh/module/ops/infrastructure/vsp/VspNotifyClientImpl.java

@@ -6,6 +6,9 @@ import com.viewsh.module.ops.infrastructure.vsp.dto.VspSendCardReqDTO;
 import com.viewsh.module.ops.infrastructure.vsp.dto.VspSyncStatusReqDTO;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
 import org.springframework.web.client.HttpStatusCodeException;
 import org.springframework.web.client.ResourceAccessException;
@@ -44,9 +47,13 @@ public class VspNotifyClientImpl implements VspNotifyClient {
 
     private void executeWithRetry(String url, Object req,
                                   String action, String orderId, String alarmId) {
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+        HttpEntity<Object> entity = new HttpEntity<>(req, headers);
+
         for (int i = 0; i <= properties.getMaxRetry(); i++) {
             try {
-                VspResponseDTO resp = restTemplate.postForObject(url, req, VspResponseDTO.class);
+                VspResponseDTO resp = restTemplate.postForObject(url, entity, VspResponseDTO.class);
                 if (resp != null && resp.isSuccess()) {
                     log.info("[{}] vsp通知成功, orderId={}, alarmId={}", action, orderId, alarmId);
                     return;