Book with active loan can still be deleted

[FadlallaIbrahemAbdou]

Title: Book with active loan can still be deleted
Description:
A book that currently has an active loan can be deleted, leaving inconsistent loan data.
Steps to Reproduce:

1. Identify a book that is currently on loan.
2. Open the Books list.
3. Click Delete on that book and confirm.
   Expected Result:
   Deletion is blocked and a message indicates the book has active loans.
   Actual Result:
   Book is deleted while the loan record still exists.
   Severity: High
   Priority: P1
   Status: New
   Environment: Chrome 129, Windows 11
   Screenshot / Evidence: