feat: support custom tracker url (#59)

ui/flutter/lib/core/common/libgopeed_ffi.dart

@@ -20,7 +20,7 @@ class LibgopeedFFi implements LibgopeedInterface {
     var completer = Completer<int>();
     var result = _libgopeed.Start(jsonEncode(cfg).toNativeUtf8().cast());
     if (result.r1 != nullptr) {
-      completer.completeError(result.r1.cast<Utf8>().toDartString());
+      completer.completeError(Exception(result.r1.cast<Utf8>().toDartString()));
     } else {
       completer.complete(result.r0);
     }

ui/flutter/lib/core/common/start_config.dart

@@ -4,19 +4,14 @@ part 'start_config.g.dart';
 
 @JsonSerializable()
 class StartConfig {
-  String network;
-  String address;
-  String storage;
-  String storageDir;
-  int refreshInterval;
+  late String network;
+  late String address;
+  late String storage;
+  late String storageDir;
+  late int refreshInterval;
+  late String apiToken;
 
-  StartConfig({
-    required this.network,
-    required this.address,
-    required this.storage,
-    required this.storageDir,
-    required this.refreshInterval,
-  });
+  StartConfig();
 
   factory StartConfig.fromJson(Map<String, dynamic> json) =>
       _$StartConfigFromJson(json);

ui/flutter/lib/core/common/start_config.g.dart

@@ -6,13 +6,13 @@ part of 'start_config.dart';
 // JsonSerializableGenerator
 // **************************************************************************
 
-StartConfig _$StartConfigFromJson(Map<String, dynamic> json) => StartConfig(
-      network: json['network'] as String,
-      address: json['address'] as String,
-      storage: json['storage'] as String,
-      storageDir: json['storageDir'] as String,
-      refreshInterval: json['refreshInterval'] as int,
-    );
+StartConfig _$StartConfigFromJson(Map<String, dynamic> json) => StartConfig()
+  ..network = json['network'] as String
+  ..address = json['address'] as String
+  ..storage = json['storage'] as String
+  ..storageDir = json['storageDir'] as String
+  ..refreshInterval = json['refreshInterval'] as int
+  ..apiToken = json['apiToken'] as String;
 
 Map<String, dynamic> _$StartConfigToJson(StartConfig instance) =>
     <String, dynamic>{
@@ -21,4 +21,5 @@ Map<String, dynamic> _$StartConfigToJson(StartConfig instance) =>
       'storage': instance.storage,
       'storageDir': instance.storageDir,
       'refreshInterval': instance.refreshInterval,
+      'apiToken': instance.apiToken,
     };