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_

CloudStack UI の Instance → Backup 削除フローと、レポートに表示されている Veeam provider の警告から調査を開始します。CloudStack 4.21.0.0 と Veeam 12.3.2.3617 で再現し、UI レコードの削除が provider 側の削除と一致するかを追跡します。レポートでは期待される動作が定義されていないため、コーディングの前に、単一のリストアポイントの削除と retention cleanup の基準を明確にしてください。

索引モデルが issue の本文から書いたものです。