ON DELETE CASCADE can be dangerous when used with applications that expect to be notified of deletions, like in your case.
Ideally, everything that needs to change when a row is deleted would be changed automatically and atomically using database-side constraints and triggers. In practice, applications often need to sync state with external services that the database knows nothing about, so I understand your concerns.
ON DELETE RESTRICT, on the other hand, will result in errors just like any other query error that you can handle in your application. Nothing happened, so there's nothing to be notified of.
Ideally, everything that needs to change when a row is deleted would be changed automatically and atomically using database-side constraints and triggers. In practice, applications often need to sync state with external services that the database knows nothing about, so I understand your concerns.
ON DELETE RESTRICT, on the other hand, will result in errors just like any other query error that you can handle in your application. Nothing happened, so there's nothing to be notified of.