feat: remove applications with ghosted, rejected, withdrawn

- applications with this status will be removed after 3-7 days since last update.

Look for where application statuses are tracked and updated, likely in a data model or service file. Identify the logic for marking applications as ghosted, rejected, or withdrawn, and then implement a cleanup job or scheduled task that removes records based on their last update timestamp. Check for existing tests around application lifecycle or cleanup to understand the expected behavior.

Vom Indexierungsmodell aus dem Issue-Text verfasst.