improving ntfy error handling

lib/notification/adapter/ntfy.js

@@ -36,6 +36,16 @@ Link: ${newListing.link}`;
       method: 'POST',
       headers,
       body: message,
+    })
+      .then((res) => {
+        if (!res.ok) {
+          throw new Error(`Ntfy message could not be sent. Status code: ${res.status}`);
+        }
+        return res.text();
+      })
+      .catch((error) => {
+        // Ensure we reject with an Error object and prevent unhandled rejections
+        throw error instanceof Error ? error : new Error(String(error));
       });
   });