some fixes

test/data/sync/sync_engine_test.dart

@@ -11,7 +11,6 @@ import 'package:app_boilerplate/data/nostr/models/nostr_keypair.dart';
 import 'package:path/path.dart' as path;
 import 'package:sqflite_common_ffi/sqflite_ffi.dart';
 import 'package:dio/dio.dart';
-import 'dart:convert';
 
 void main() {
   // Initialize Flutter bindings and sqflite for testing
@@ -511,4 +510,3 @@ Dio _createMockDio({
 
   return dio;
 }
-