fix(file): 解决文件下载和时间戳处理问题

- 实现文件名扩展名推断逻辑，从URL路径自动提取并添加扩展名
- 添加下载错误处理和日志记录功能
- 在下载失败时显示错误通知而非成功通知
- 将服务器时间戳处理统一调整为CST（亚洲/上海）时区
- 更新sdk-core版本号至1.1.6-SNAPSHOT

Jenkinsfile

@@ -164,18 +164,26 @@ print('versions.json updated, platformVersion=' + d.get('platformVersion', ''))
           def serviceVersions = new groovy.json.JsonSlurperClassic().parseText(env.SERVICE_VERSIONS_JSON)
           def versionFiles = serviceVersions.keySet().collect { "VERSION.${it}" }.join(' ')
           def summary = serviceVersions.collect { svc, ver -> "${svc}=${ver}" }.join(', ')
+          // 先本地提交（幂等）
           bat """
             chcp 65001 >nul
             git config user.email "jenkins@xuqm.com"
             git config user.name "Jenkins CI"
             git add ${versionFiles}
             git diff --cached --quiet || git commit -m "ci: bump versions [${summary}] [skip ci]"
+          """
+          // push 加 retry + rebase，应对多 job 并发推送冲突
+          retry(3) {
+            bat """
+              chcp 65001 >nul
+              git pull --rebase origin main
               git push origin HEAD:main
             """
           }
         }
       }
     }
+  }
 
   post {
     success {

push-service/src/main/java/com/xuqm/push/entity/DeviceTokenEntity.java

@@ -58,6 +58,12 @@ public class DeviceTokenEntity {
     @Column(nullable = false)
     private boolean receivePush = true;
 
+    @Column(length = 16)
+    private String appState; // FOREGROUND | BACKGROUND | TERMINATED
+
+    @Column
+    private LocalDateTime appStateAt;
+
     @Column
     private LocalDateTime lastLoginAt;