Connect sign-up to Sendico Facts intake (#46)

frontend/app/lib/auth/feedback.dart

@@ -22,6 +22,7 @@ class AuthFeedback extends StatelessWidget {
             AuthError.accountNotVerified => l.authVerifyEmail,
             AuthError.invalidCredentials => l.authInvalidCredentials,
             AuthError.emailInUse => l.authEmailInUse,
+            AuthError.signupNeedsAssistance => l.authSignupNeedsAssistance,
             AuthError.unavailable => l.authUnavailable,
             AuthError.unexpected => l.authUnexpected,
             AuthError.factorLocked => l.factorLocked,

frontend/app/lib/l10n/en.arb

@@ -1,5 +1,6 @@
 {
   "@@locale": "en",
+  "authSignupNeedsAssistance": "We could not finish setting up your account. Please contact support.",
   "appTitle": "SXCHNGE · Your next move",
   "nextChapter": "YOUR NEXT CHAPTER",
   "loginHeading": "Hey, welcome\nback.",

frontend/app/lib/l10n/ru.arb

@@ -1,5 +1,6 @@
 {
   "@@locale": "ru",
+  "authSignupNeedsAssistance": "Не удалось завершить создание аккаунта. Обратитесь в службу поддержки.",
   "appTitle": "SXCHNGE · Ваш следующий шаг",
   "nextChapter": "НОВАЯ ГЛАВА",
   "loginHeading": "Рады видеть\nвас снова.",

frontend/app/lib/verification/page.dart

@@ -122,8 +122,10 @@ class _VerificationPageState extends State<VerificationPage> {
               (_provider.service as SimulationInfo).isSimulated) ||
           state.isSimulated;
       final sent = status == VerificationStatus.sent;
+      final needsAssistance = state.error == VerificationError.needsAssistance;
       final retryConfirmation =
           status == VerificationStatus.error &&
+          !needsAssistance &&
           !_lastWasSend &&
           widget.token != null;
       final title = switch (status) {
@@ -139,14 +141,16 @@ class _VerificationPageState extends State<VerificationPage> {
               ? l.verificationChecking
               : l.verificationRequest,
       };
-      final body = switch (status) {
-        VerificationStatus.sent => l.verificationSent,
-        VerificationStatus.verified => l.verificationVerifiedBody,
-        VerificationStatus.expired => l.verificationExpiredBody,
-        VerificationStatus.invalid => l.verificationInvalidBody,
-        VerificationStatus.error => l.verificationInternalBody,
-        _ => null,
-      };
+      final body = needsAssistance
+          ? l.authSignupNeedsAssistance
+          : switch (status) {
+              VerificationStatus.sent => l.verificationSent,
+              VerificationStatus.verified => l.verificationVerifiedBody,
+              VerificationStatus.expired => l.verificationExpiredBody,
+              VerificationStatus.invalid => l.verificationInvalidBody,
+              VerificationStatus.error => l.verificationInternalBody,
+              _ => null,
+            };
       return Scaffold(
         body: SafeArea(
           child: SingleChildScrollView(