Bug: MemberOverview should not include entries that are marked as deleted

[ManuelMoeri]

Description

The current implementation of the DB member-view has a crucial mistake. Since the view is built on db level it was forgotten to filter out all entries like certificates, degrees and whatsoever that are flagged with the 'deleted_at' attribute. This causes the view to provide entries that should be deleted.

We could also filter this out in the backend, but since we don't have a usecase for the deleted entries anyways we might as well just re-build our view to filter them out on DB level.

Acceptance Criteria

• The view no longer provides entries that are marked as deleted
• The solution was built on DB level
• The rest of the view remains unchanged
• Perform smoke tests and add integration tests to ensure it works properly

Additional Information

• The last change to the DB view was made in the V0_0_20 migration (as of 22.04.2026), which represents the newest version