merge functionality of kiosk + logged in -> allow kiosk to have fördernde people as rower in logbook

src/model/user/basic.rs

@@ -529,6 +529,13 @@ impl User {
     }
 
     pub(crate) async fn remove_membership_pdf(&self, db: &SqlitePool, updated_by: &ManageUserUser) {
+        ActivityBuilder::new(&format!(
+            "{updated_by} hat die Beitrittserklärung vom Beutzer gelöscht."
+        ))
+        .user(self)
+        .save(db)
+        .await;
+
         sqlx::query!(
             "UPDATE user SET membership_pdf = null where id = ?",
             self.id