feat(core): switch to native fetch API for all HTTP requests

ts/bunq.classes.export.ts

@@ -114,14 +114,19 @@ export class BunqExport {
     // For PDF statements, use the /content endpoint directly
     const downloadUrl = `${this.bunqAccount.apiContext.getBaseUrl()}/v1/user/${this.bunqAccount.userId}/monetary-account/${this.monetaryAccount.id}/customer-statement/${this.id}/content`;
 
-    const response = await plugins.smartrequest.request(downloadUrl, {
+    const response = await fetch(downloadUrl, {
       method: 'GET',
       headers: {
         'X-Bunq-Client-Authentication': this.bunqAccount.apiContext.getSession().getContext().sessionToken
       }
     });
 
-    return Buffer.from(response.body);
+    if (!response.ok) {
+      throw new Error(`Failed to download export: HTTP ${response.status}`);
+    }
+
+    const arrayBuffer = await response.arrayBuffer();
+    return Buffer.from(arrayBuffer);
   }
 
   /**