fix: use relayAbort helper for addEventListener to preserve AbortError reason

src/utils/fetch-timeout.ts

@@ -1,3 +1,16 @@
+/**
+ * Relay abort without forwarding the Event argument as the abort reason.
+ * Using .bind() avoids closure scope capture (memory leak prevention).
+ */
+function relayAbort(this: AbortController) {
+  this.abort();
+}
+
+/** Returns a bound abort relay for use as an event listener. */
+export function bindAbortRelay(controller: AbortController): () => void {
+  return relayAbort.bind(controller);
+}
+
 /**
  * Fetch wrapper that adds timeout support via AbortController.
  *