test(app): the password cubits' states, every refusal included

Signing in (a code, a recovery code, an account never finished, a lost
authenticator by mail and by phrase, an impostor instance, no
connection), setting up (signing up, a password for someone signed in,
finishing an account's reset with new keys or the old), getting back in
(with the phrase, starting a reset without it) and the account section
(what keeps the account, its steps, adding an authenticator, a new
phrase), each as the states it emits.

They found that reading what keeps the account wrapped two refusals at
once in a ParallelWaitError, which no caller takes for one: offline, the
account section showed nothing. The first refusal now goes up as it is.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_app/test/password/bloc/states.dart

@@ -0,0 +1,28 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/halkyon_app.dart';
+
+/// The states [cubit] emits while [step] runs, in order.
+Future<List<S>> statesOf<S>(
+  BlocBase<S> cubit,
+  Future<void> Function() step,
+) async {
+  final states = <S>[];
+  final listening = cubit.stream.listen(states.add);
+  await step();
+  // A cubit's stream hands its states on in a microtask.
+  await Future<void>.delayed(Duration.zero);
+  await listening.cancel();
+  return states;
+}
+
+/// The states [cubit] emits as [step] (not awaited: it emits at once).
+Future<List<S>> statesNow<S>(BlocBase<S> cubit, void Function() step) =>
+    statesOf(cubit, () async => step());
+
+/// A refusal of [problem].
+Matcher refusedAs(PasswordProblem problem) => isA<PasswordFailed>().having(
+  (failed) => failed.problem,
+  'problem',
+  problem,
+);