added support for multiple accounts, guardian login bugfixes, ui changes

lib/state/app/modules/account/bloc/account_bloc.dart

@@ -4,12 +4,38 @@ import 'account_event.dart';
 import 'account_state.dart';
 
 class AccountBloc extends Bloc<AccountEvent, AccountState> {
-  AccountBloc({AccountStatus initialStatus = AccountStatus.undefined})
-    : super(AccountState(status: initialStatus)) {
+  AccountBloc({
+    AccountStatus initialStatus = AccountStatus.undefined,
+    String? accountId,
+  }) : super(AccountState(status: initialStatus, accountId: accountId)) {
     on<AccountStatusChanged>(
-      (event, emit) => emit(state.copyWith(status: event.status)),
+      (event, emit) => emit(
+        AccountState(
+          status: event.status,
+          accountId: event.status == AccountStatus.loggedOut
+              ? null
+              : state.accountId,
+        ),
+      ),
+    );
+    on<AccountActivated>(
+      (event, emit) => emit(
+        AccountState(
+          status: AccountStatus.loggedIn,
+          accountId: event.accountId,
+          freshLogin: event.freshLogin,
+        ),
+      ),
     );
   }
 
   void setStatus(AccountStatus status) => add(AccountStatusChanged(status));
+
+  /// [accountId] became the active account (login, switch or takeover after a
+  /// sign-out); null means no account is left.
+  void activated(String? accountId, {bool freshLogin = false}) => add(
+    accountId == null
+        ? const AccountStatusChanged(AccountStatus.loggedOut)
+        : AccountActivated(accountId, freshLogin: freshLogin),
+  );
 }

lib/state/app/modules/account/bloc/account_event.dart

@@ -8,3 +8,9 @@ class AccountStatusChanged extends AccountEvent {
   final AccountStatus status;
   const AccountStatusChanged(this.status);
 }
+
+class AccountActivated extends AccountEvent {
+  final String accountId;
+  final bool freshLogin;
+  const AccountActivated(this.accountId, {required this.freshLogin});
+}

lib/state/app/modules/account/bloc/account_state.dart

@@ -1,9 +1,18 @@
-enum AccountStatus { undefined, loggedIn, loggedOut }
+enum AccountStatus { undefined, loggedIn, loggedOut, addingAccount }
 
 class AccountState {
   final AccountStatus status;
-  const AccountState({this.status = AccountStatus.undefined});
 
-  AccountState copyWith({AccountStatus? status}) =>
-      AccountState(status: status ?? this.status);
+  /// Active account; the account-scoped part of the app is keyed by it.
+  final String? accountId;
+
+  /// Set when [accountId] came from a login (not a switch), to show the
+  /// post-login splash.
+  final bool freshLogin;
+
+  const AccountState({
+    this.status = AccountStatus.undefined,
+    this.accountId,
+    this.freshLogin = false,
+  });
 }