fix: 完善自动导入异常中断与恢复

- 自动导入基础设施异常触发批次熔断，保留完整日志并输出安全错误信息

- 增加恢复令牌与租约围栏、无文档失败项重建及消息退避机制

- 前端展示中断状态并在状态请求失败后自动恢复轮询

- 补充批次中断迁移、配置与并发异常路径测试

easyflow-ui-admin/app/src/locales/langs/en-US/documentCollection.json

@@ -116,6 +116,10 @@
     "pendingCount": "Pending",
     "skippedCount": "Skipped",
     "continueBatch": "Continue",
+    "batchStatusLoadFailed": "Unable to load the automatic import status. Retrying automatically.",
+    "interruptFallback": "Automatic import was interrupted. Resume after the service recovers.",
+    "interruptCode": "Error code",
+    "interruptedAt": "Interrupted at",
     "splitOrIndexFailed": "Chunking or indexing failed. Please retry.",
     "documentSourceUnavailable": "Unable to read the document file. Please contact the administrator.",
     "parseServiceUnavailable": "The document parsing service is temporarily unavailable. Please retry later.",