bugfix:

when the bookmark list is empty, the script tried eternally to load more bookmarks.
resolved by introducing a check

frontend/src/routes/bookmark/Index.svelte

@@ -55,8 +55,8 @@
             bookmarks = Object.values(merged).sort((a, b) => new Date(b.timestamp) - new Date(a.timestamp));
             loader.offset += loader.limit;
             loader.active  = false;
-            error = false;
-            onscroll(null);
+            error = null;
+            if (Object.keys(raw).length) onscroll(null); // when bookmarks were received, check whether they fill up the page
         } else {
             error = await resp.html();
         }