Implement NStore interface from NLib

src/utils/abort.ts

@@ -0,0 +1,6 @@
+/** Creates an `AbortError` object matching the Fetch API. */
+function abortError() {
+  return new DOMException('The signal has been aborted', 'AbortError');
+}
+
+export { abortError };

src/utils/api.ts

@@ -51,7 +51,7 @@ async function updateEvent<K extends number, E extends EventStub>(
   fn: (prev: NostrEvent | undefined) => E,
   c: AppContext,
 ): Promise<NostrEvent> {
-  const [prev] = await eventsDB.filter([filter], { limit: 1 });
+  const [prev] = await eventsDB.query([filter], { limit: 1 });
   return createEvent(fn(prev), c);
 }