fix don'r remove orphaned whiteboards

src/main/frontend/db/model.cljs

@@ -1697,6 +1697,7 @@ independent of format as format specific heading characters are stripped"
                                     (= 1 (count children))
                                     (contains? #{"" "-" "*"} (string/trim (:block/content first-child))))))
                                 (not (contains? built-in-pages name))
+                                (not (= "whiteboard" (:block/type page)))
                                 (not (:block/_namespace page))
                                  ;; a/b/c might be deleted but a/b/c/d still exists (for backward compatibility)
                                 (not (and (string/includes? name "/")