feat(useragent): initial impl

useragent/lib/providers/key.dart

@@ -0,0 +1,60 @@
+import 'package:hooks_riverpod/experimental/mutation.dart';
+import 'package:mtcore/markettakers.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:arbiter/features/pk_manager.dart';
+import 'package:arbiter/features/simple_ed25519.dart';
+
+part 'key.g.dart';
+
+@riverpod
+KeyManager keyManager(Ref ref) {
+  return SimpleEd25519Manager();
+}
+
+@riverpod
+class Key extends _$Key {
+  @override
+  Future<KeyHandle?> build() async {
+    final manager = SimpleEd25519Manager();
+    final keyHandle = await manager.get();
+    return keyHandle;
+  }
+
+  Future<void> create() async {
+    if (state.value != null) {
+      return;
+    }
+
+    state = await AsyncValue.guard(() async {
+      final manager = SimpleEd25519Manager();
+      final newKeyHandle = await manager.create();
+      return newKeyHandle;
+    });
+  }
+}
+
+class KeyBootstrapper implements StageFactory {
+  final MutationTarget ref;
+
+  KeyBootstrapper({required this.ref});
+
+  @override
+  String get title => "Setting up your identity";
+
+  @override
+  Future<bool> get isAlreadyCompleted async {
+    final key = await ref.container.read(keyProvider.future);
+    return key != null;
+  }
+
+  @override
+  Future<void> start(StageController controller) async {
+    controller.setIndefiniteProgress();
+    final key = ref.container.read(keyProvider.notifier);
+
+    await key.create();
+  }
+
+  @override
+  void dispose() {}
+}