Veeam plugin – Deleting single backup from CloudStack UI removes entire backup chain in UI while data remains in Veeam

### problem

We recently completed the integration between Veeam Backup & Replication and Apache CloudStack by following the official documentation, and the backup workflow is generally operational. However, we have encountered an unexpected behavior in the backup deletion process.

When attempting to delete a single backup from the CloudStack UI (Instance → Backup section), the following message is displayed:

Veeam backup provider does not have a safe way to remove a single restore point, which results in all backup chain being removed. Use forced:true to skip this verification and remove the complete backup chain.

After proceeding with force delete, all backup entries for the VM are removed from the CloudStack UI. However, the actual backup files still remain intact on the Veeam server and are not physically deleted.

Observed issues:

1.CloudStack UI removes the entire backup chain when deleting a single backup.

2.This creates operational problems for quota management. For example, with a backup limit of 20, users should be able to delete older restore points individually.

3.Even when the Veeam job is configured for full backups (not incremental), the same behavior occurs.

4.Although the retention policy on the Veeam template job is set to 7 days, backups older than one month are still present and not automatically cleaned up in either CloudStack or Veeam.

Could you please advise how this situation should be properly handled or configured to avoid this behavior?

### versions

CloudStack 4.21.0.0
veeam 12.3.2.3617

### The steps to reproduce the bug

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### What to do about it?

_No response_

从 CloudStack UI 的 Instance → Backup 删除流程以及报告中显示的 Veeam provider 警告开始；在 CloudStack 4.21.0.0 和 Veeam 12.3.2.3617 上复现，并跟踪 UI 记录移除是否与 provider 端删除一致。报告没有定义预期行为，因此请在编码前明确单个还原点删除和 retention cleanup 的标准。

由索引模型根据 Issue 内容生成。