refactor(legacy_seed_view): sanitize user-facing error messages

lib/features/legacy_seed_view/domain/get_legacy_seeds_usecase.dart

@@ -0,0 +1,67 @@
+import 'package:bb_mobile/core/storage/data/datasources/key_value_storage/keychain_locked_exception.dart';
+import 'package:bb_mobile/core/storage/migrations/005_hive_to_sqlite/get_old_seeds_usecase.dart';
+import 'package:bb_mobile/core/storage/migrations/005_hive_to_sqlite/old/entities/old_seed.dart';
+import 'package:bb_mobile/core/utils/logger.dart';
+import 'package:bb_mobile/core/utils/result.dart';
+import 'package:bb_mobile/features/legacy_seed_view/domain/legacy_seed_view_failure.dart';
+import 'package:meta/meta.dart';
+
+/// Feature boundary: wraps the shared core [GetOldSeedsUsecase] (which still
+/// throws) in the first layer this feature owns. Logs sanitized exception
+/// metadata and returns a typed [LegacySeedViewFailure] so nothing above ever
+/// sees raw exception text.
+class GetLegacySeedsUsecase {
+  final GetOldSeedsUsecase _getOldSeedsUsecase;
+
+  GetLegacySeedsUsecase({required this._getOldSeedsUsecase});
+
+  @useResult
+  Future<Result<List<OldSeed>, LegacySeedViewFailure>> execute() async {
+    try {
+      final seeds = await _getOldSeedsUsecase.execute();
+      return Ok(_dedupeByMnemonic(seeds));
+    } on KeychainLockedException catch (e, st) {
+      // Exceptions from this secret-bearing flow may contain key material.
+      // Record the safe type and trace, never the exception payload itself.
+      log.warning(
+        'fetch legacy seeds unavailable (${e.runtimeType})',
+        error: e.runtimeType,
+        trace: st,
+      );
+      return const Err(LegacySeedViewFetchFailure());
+    } catch (e, st) {
+      log.severe(
+        message: 'fetch legacy seeds failed (${e.runtimeType})',
+        error: e.runtimeType,
+        trace: st,
+      );
+      return const Err(LegacySeedViewUnexpectedFailure());
+    }
+  }
+
+  /// Collapses seeds that share a mnemonic into one entry, merging their
+  /// passphrases (deduplicated by passphrase + source fingerprint).
+  List<OldSeed> _dedupeByMnemonic(List<OldSeed> seeds) {
+    final mnemonicMap = <String, OldSeed>{};
+    for (final seed in seeds) {
+      final existing = mnemonicMap[seed.mnemonic];
+      if (existing == null) {
+        mnemonicMap[seed.mnemonic] = seed;
+        continue;
+      }
+      mnemonicMap[seed.mnemonic] = existing.copyWith(
+        passphrases: [
+          ...existing.passphrases,
+          ...seed.passphrases.where(
+            (p) => !existing.passphrases.any(
+              (ep) =>
+                  ep.passphrase == p.passphrase &&
+                  ep.sourceFingerprint == p.sourceFingerprint,
+            ),
+          ),
+        ],
+      );
+    }
+    return mnemonicMap.values.toList();
+  }
+}

lib/features/legacy_seed_view/domain/legacy_seed_view_failure.dart

@@ -0,0 +1,13 @@
+import 'package:bb_mobile/core/failures/failure.dart';
+
+sealed class LegacySeedViewFailure extends Failure {
+  const LegacySeedViewFailure([super.logMessage]);
+}
+
+final class LegacySeedViewFetchFailure extends LegacySeedViewFailure {
+  const LegacySeedViewFetchFailure([super.logMessage]);
+}
+
+final class LegacySeedViewUnexpectedFailure extends LegacySeedViewFailure {
+  const LegacySeedViewUnexpectedFailure([super.logMessage]);
+}

lib/features/legacy_seed_view/legacy_seed_view_locator.dart

@@ -1,12 +1,18 @@
 import 'package:bb_mobile/core/storage/migrations/005_hive_to_sqlite/get_old_seeds_usecase.dart';
+import 'package:bb_mobile/features/legacy_seed_view/domain/get_legacy_seeds_usecase.dart';
 import 'package:bb_mobile/features/legacy_seed_view/presentation/legacy_seed_view_cubit.dart';
 import 'package:get_it/get_it.dart';
 
 class LegacySeedViewLocator {
   static void setup(GetIt locator) {
+    locator.registerFactory<GetLegacySeedsUsecase>(
+      () => GetLegacySeedsUsecase(
+        getOldSeedsUsecase: locator<GetOldSeedsUsecase>(),
+      ),
+    );
     locator.registerFactory<LegacySeedViewCubit>(
       () => LegacySeedViewCubit(
-        getOldSeedsUsecase: locator<GetOldSeedsUsecase>(),
+        getLegacySeedsUsecase: locator<GetLegacySeedsUsecase>(),
       ),
     );
   }

lib/features/legacy_seed_view/presentation/legacy_seed_view_cubit.dart

@@ -1,50 +1,26 @@
-import 'package:bb_mobile/core/storage/migrations/005_hive_to_sqlite/get_old_seeds_usecase.dart';
 import 'package:bb_mobile/core/storage/migrations/005_hive_to_sqlite/old/entities/old_seed.dart';
+import 'package:bb_mobile/core/utils/result.dart';
+import 'package:bb_mobile/features/legacy_seed_view/domain/get_legacy_seeds_usecase.dart';
+import 'package:bb_mobile/features/legacy_seed_view/domain/legacy_seed_view_failure.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 
 part 'legacy_seed_view_cubit.freezed.dart';
 part 'legacy_seed_view_state.dart';
 
 class LegacySeedViewCubit extends Cubit<LegacySeedViewState> {
-  LegacySeedViewCubit({required this._getOldSeedsUsecase})
-    : super(const LegacySeedViewState());
+  final GetLegacySeedsUsecase _getLegacySeedsUsecase;
 
-  final GetOldSeedsUsecase _getOldSeedsUsecase;
+  LegacySeedViewCubit({required this._getLegacySeedsUsecase})
+    : super(const LegacySeedViewState());
 
   Future<void> fetchOldSeeds() async {
-    emit(state.copyWith(loading: true, error: null));
-    try {
-      final seeds = await _getOldSeedsUsecase.execute();
-      final Map<String, OldSeed> mnemonicMap = {};
-      for (final seed in seeds) {
-        if (mnemonicMap.containsKey(seed.mnemonic)) {
-          final existing = mnemonicMap[seed.mnemonic]!;
-          mnemonicMap[seed.mnemonic] = existing.copyWith(
-            passphrases: [
-              ...existing.passphrases,
-              ...seed.passphrases.where(
-                (p) => !existing.passphrases.any(
-                  (ep) =>
-                      ep.passphrase == p.passphrase &&
-                      ep.sourceFingerprint == p.sourceFingerprint,
-                ),
-              ),
-            ],
-          );
-        } else {
-          mnemonicMap[seed.mnemonic] = seed;
-        }
-      }
-      emit(
-        state.copyWith(
-          loading: false,
-          seeds: mnemonicMap.values.toList(),
-          error: null,
-        ),
-      );
-    } catch (e) {
-      emit(state.copyWith(loading: false, error: e.toString()));
+    emit(state.copyWith(loading: true, failure: null));
+    switch (await _getLegacySeedsUsecase.execute()) {
+      case Ok(:final value):
+        emit(state.copyWith(loading: false, seeds: value, failure: null));
+      case Err(:final failure):
+        emit(state.copyWith(loading: false, failure: failure));
     }
   }
 

lib/features/legacy_seed_view/presentation/legacy_seed_view_failure_l10n.dart

@@ -0,0 +1,10 @@
+import 'package:bb_mobile/core/utils/build_context_x.dart';
+import 'package:bb_mobile/features/legacy_seed_view/domain/legacy_seed_view_failure.dart';
+import 'package:flutter/widgets.dart';
+
+extension LegacySeedViewFailureL10n on LegacySeedViewFailure {
+  String toTranslated(BuildContext context) => switch (this) {
+    LegacySeedViewFetchFailure() => context.loc.legacySeedViewErrorFetch,
+    LegacySeedViewUnexpectedFailure() => context.loc.oopsSomethingWentWrong,
+  };
+}

lib/features/legacy_seed_view/presentation/legacy_seed_view_state.dart

@@ -5,7 +5,7 @@ abstract class LegacySeedViewState with _$LegacySeedViewState {
   const factory LegacySeedViewState({
     @Default(<OldSeed>[]) List<OldSeed> seeds,
     @Default(false) bool loading,
-    String? error,
+    LegacySeedViewFailure? failure,
   }) = _LegacySeedViewState;
   const LegacySeedViewState._();
 }

lib/features/legacy_seed_view/ui/legacy_seed_view_screen.dart

@@ -2,12 +2,27 @@ import 'package:bb_mobile/core/themes/app_theme.dart';
 import 'package:bb_mobile/core/utils/build_context_x.dart';
 import 'package:bb_mobile/core/widgets/text/text.dart';
 import 'package:bb_mobile/features/legacy_seed_view/presentation/legacy_seed_view_cubit.dart';
+import 'package:bb_mobile/features/legacy_seed_view/presentation/legacy_seed_view_failure_l10n.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
-class LegacySeedViewScreen extends StatelessWidget {
+class LegacySeedViewScreen extends StatefulWidget {
   const LegacySeedViewScreen({super.key});
 
+  @override
+  State<LegacySeedViewScreen> createState() => _LegacySeedViewScreenState();
+}
+
+class _LegacySeedViewScreenState extends State<LegacySeedViewScreen> {
+  @override
+  void initState() {
+    super.initState();
+    // Fetch once on mount. Triggering the fetch from BlocBuilder.builder
+    // instead re-fires on every rebuild when the result is an empty success
+    // (the user has no legacy seeds), which loops indefinitely.
+    context.read<LegacySeedViewCubit>().fetchOldSeeds();
+  }
+
   @override
   Widget build(BuildContext context) {
     return PopScope(
@@ -25,15 +40,15 @@ class LegacySeedViewScreen extends StatelessWidget {
         ),
         body: BlocBuilder<LegacySeedViewCubit, LegacySeedViewState>(
           builder: (context, state) {
-            if (!state.loading && state.seeds.isEmpty && state.error == null) {
-              context.read<LegacySeedViewCubit>().fetchOldSeeds();
-            }
             if (state.loading) {
               return const Center(child: CircularProgressIndicator());
             }
-            if (state.error != null) {
+            if (state.failure case final failure?) {
               return Center(
-                child: BBText(state.error!, style: context.font.bodyLarge),
+                child: BBText(
+                  failure.toTranslated(context),
+                  style: context.font.bodyLarge,
+                ),
               );
             }
             if (state.seeds.isEmpty) {

localization/app_ar.arb

@@ -13281,5 +13281,6 @@
   "receiveMessageForSender": "رسالة إلى المرسل",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "تم تفعيل Payjoin، لكن هذه المحفظة لا تحتوي بعد على رصيد للمساهمة. سيتم تفعيله بمجرد استلام أموال.",
-  "announcementAutoswapDescription": "يتم تحويل رصيد Liquid الخاص بك تلقائيًا إلى Bitcoin."
+  "announcementAutoswapDescription": "يتم تحويل رصيد Liquid الخاص بك تلقائيًا إلى Bitcoin.",
+  "legacySeedViewErrorFetch": "فشل تحميل البذور القديمة. يرجى المحاولة مرة أخرى."
 }

localization/app_as.arb

@@ -10325,5 +10325,6 @@
   "receiveMessageForSender": "প্ৰেৰকৰ বাবে বাৰ্তা",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin সক্ৰিয় কৰা হৈছে, কিন্তু এই ৱালেটত এতিয়াও অৱদান দিবলৈ কোনো বেলেঞ্চ নাই। আপুনি ধন লাভ কৰিলেই ই সক্ৰিয় হ’ব।",
-  "announcementAutoswapDescription": "আপোনাৰ Liquid স্বয়ংক্ৰিয়ভাৱে Bitcoin-লৈ ৰূপান্তৰ কৰা হয়।"
+  "announcementAutoswapDescription": "আপোনাৰ Liquid স্বয়ংক্ৰিয়ভাৱে Bitcoin-লৈ ৰূপান্তৰ কৰা হয়।",
+  "legacySeedViewErrorFetch": "পুৰণা ছীড লোড কৰিব পৰা নগ’ল। অনুগ্ৰহ কৰি পুনৰ চেষ্টা কৰক।"
 }

localization/app_bg.arb

@@ -10967,5 +10967,6 @@
   "receiveMessageForSender": "Съобщение за изпращача",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin е активиран, но този портфейл все още няма наличност за участие. Ще се активира, щом получите средства.",
-  "announcementAutoswapDescription": "Вашият Liquid се обменя автоматично за Bitcoin."
+  "announcementAutoswapDescription": "Вашият Liquid се обменя автоматично за Bitcoin.",
+  "legacySeedViewErrorFetch": "Неуспешно зареждане на наследените семена. Моля, опитайте отново."
 }

localization/app_bn.arb

@@ -13488,5 +13488,6 @@
   "receiveMessageForSender": "প্রেরকের জন্য বার্তা",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin চালু আছে, কিন্তু এই ওয়ালেটে অবদান রাখার মতো কোনো ব্যালেন্স নেই। অর্থ পাওয়ার পর এটি সক্রিয় হবে।",
-  "announcementAutoswapDescription": "আপনার Liquid স্বয়ংক্রিয়ভাবে Bitcoin-এ রূপান্তরিত হয়।"
+  "announcementAutoswapDescription": "আপনার Liquid স্বয়ংক্রিয়ভাবে Bitcoin-এ রূপান্তরিত হয়।",
+  "legacySeedViewErrorFetch": "পুরোনো সিড লোড করা যায়নি। অনুগ্রহ করে আবার চেষ্টা করুন।"
 }

localization/app_cs.arb

@@ -13278,5 +13278,6 @@
   "receiveMessageForSender": "Zpráva pro odesílatele",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin je povolen, ale tato peněženka zatím nemá zůstatek, kterým by mohla přispět. Aktivuje se, jakmile obdržíte prostředky.",
-  "announcementAutoswapDescription": "Váš Liquid se automaticky směňuje za Bitcoin."
+  "announcementAutoswapDescription": "Váš Liquid se automaticky směňuje za Bitcoin.",
+  "legacySeedViewErrorFetch": "Nepodařilo se načíst starší seedy. Zkuste to prosím znovu."
 }

localization/app_de.arb

@@ -5221,5 +5221,6 @@
   "receiveMessageForSender": "Nachricht an den Sender",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin ist aktiviert, aber dieses Wallet hat noch kein Guthaben für einen Beitrag. Es wird aktiv, sobald du Guthaben empfängst.",
-  "announcementAutoswapDescription": "Dein Liquid wird automatisch in Bitcoin getauscht."
+  "announcementAutoswapDescription": "Dein Liquid wird automatisch in Bitcoin getauscht.",
+  "legacySeedViewErrorFetch": "Legacy-Seeds konnten nicht geladen werden. Bitte versuchen Sie es erneut."
 }

localization/app_el.arb

@@ -13278,5 +13278,6 @@
   "receiveMessageForSender": "Μήνυμα για τον αποστολέα",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Το Payjoin είναι ενεργοποιημένο, αλλά αυτό το πορτοφόλι δεν έχει ακόμη υπόλοιπο για συνεισφορά. Θα ενεργοποιηθεί μόλις λάβετε χρήματα.",
-  "announcementAutoswapDescription": "Το Liquid σας ανταλλάσσεται αυτόματα σε Bitcoin."
+  "announcementAutoswapDescription": "Το Liquid σας ανταλλάσσεται αυτόματα σε Bitcoin.",
+  "legacySeedViewErrorFetch": "Αποτυχία φόρτωσης των παλαιών seeds. Παρακαλώ δοκιμάστε ξανά."
 }

localization/app_en.arb

@@ -15024,5 +15024,9 @@
   "receivePayjoinBelowMinimumAmount": "Payjoin is off for this amount — it is below your Payjoin minimum. Request a larger amount to enable it.",
   "@receivePayjoinBelowMinimumAmount": {
     "description": "Hint on the receive screen when payjoin is enabled but the requested amount is below the anti-probing minimum, so the QR does not advertise a payjoin endpoint."
+  },
+  "legacySeedViewErrorFetch": "Failed to load legacy seeds. Please try again.",
+  "@legacySeedViewErrorFetch": {
+    "description": "Error shown when legacy seeds cannot be loaded"
   }
 }

localization/app_es.arb

@@ -5270,5 +5270,6 @@
   "receiveMessageForSender": "Mensaje para el remitente",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin está activado, pero esta cartera todavía no tiene saldo para contribuir. Se activará cuando recibas fondos.",
-  "announcementAutoswapDescription": "Tu Liquid se convierte automáticamente en Bitcoin."
+  "announcementAutoswapDescription": "Tu Liquid se convierte automáticamente en Bitcoin.",
+  "legacySeedViewErrorFetch": "No se pudieron cargar las semillas antiguas. Por favor, inténtalo de nuevo."
 }

localization/app_fa.arb

@@ -13278,5 +13278,6 @@
   "receiveMessageForSender": "پیام برای فرستنده",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin فعال است، اما این کیف پول هنوز موجودی‌ای برای مشارکت ندارد. پس از دریافت وجه فعال خواهد شد.",
-  "announcementAutoswapDescription": "Liquid شما به‌طور خودکار به Bitcoin تبدیل می‌شود."
+  "announcementAutoswapDescription": "Liquid شما به‌طور خودکار به Bitcoin تبدیل می‌شود.",
+  "legacySeedViewErrorFetch": "بارگذاری سیدهای قدیمی ناموفق بود. لطفاً دوباره تلاش کنید."
 }

localization/app_fi.arb

@@ -5270,5 +5270,6 @@
   "receiveMessageForSender": "Viesti lähettäjälle",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin on käytössä, mutta tässä lompakossa ei vielä ole osallistumiseen tarvittavaa saldoa. Se aktivoituu, kun vastaanotat varoja.",
-  "announcementAutoswapDescription": "Liquid-varasi vaihdetaan automaattisesti Bitcoiniin."
+  "announcementAutoswapDescription": "Liquid-varasi vaihdetaan automaattisesti Bitcoiniin.",
+  "legacySeedViewErrorFetch": "Vanhojen siementen lataaminen epäonnistui. Yritä uudelleen."
 }

localization/app_fr.arb

@@ -5289,5 +5289,6 @@
   "receiveAdditionalInformationPlaceholder": "Ajouter un montant ou un message pour l'expéditeur",
   "receiveMessageForSender": "Message pour l'expéditeur",
   "sendPayjoinLabel": "Payjoin",
-  "receivePayjoinAwaitingFunds": "Payjoin est activé, mais ce portefeuille n’a pas encore de solde à apporter. Il s’activera dès que vous recevrez des fonds."
+  "receivePayjoinAwaitingFunds": "Payjoin est activé, mais ce portefeuille n’a pas encore de solde à apporter. Il s’activera dès que vous recevrez des fonds.",
+  "legacySeedViewErrorFetch": "Échec du chargement des anciens mnémoniques. Veuillez réessayer."
 }

localization/app_hi.arb

@@ -13468,5 +13468,6 @@
   "receiveMessageForSender": "भेजने वाले के लिए संदेश",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin चालू है, लेकिन इस वॉलेट में योगदान देने के लिए अभी कोई बैलेंस नहीं है। धन प्राप्त होते ही यह सक्रिय हो जाएगा।",
-  "announcementAutoswapDescription": "आपका Liquid स्वचालित रूप से Bitcoin में बदल दिया जाता है।"
+  "announcementAutoswapDescription": "आपका Liquid स्वचालित रूप से Bitcoin में बदल दिया जाता है।",
+  "legacySeedViewErrorFetch": "पुराने सीड लोड करने में विफल। कृपया पुनः प्रयास करें।"
 }

localization/app_hi_Latn.arb

@@ -13673,5 +13673,6 @@
   "receiveMessageForSender": "Sender ke liye message",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin chalu hai, lekin is wallet mein yogdan dene ke liye abhi koi balance nahin hai. Funds milte hi yeh active ho jayega.",
-  "announcementAutoswapDescription": "Aapka Liquid apne aap Bitcoin mein badal diya jata hai."
+  "announcementAutoswapDescription": "Aapka Liquid apne aap Bitcoin mein badal diya jata hai.",
+  "legacySeedViewErrorFetch": "Purane seeds load karne mein vifal. Kripya punah prayas karein."
 }

localization/app_hy.arb

@@ -3748,5 +3748,6 @@
   "receiveMessageForSender": "Հաղորդագրություն ուղարկողին",
   "sendPayjoinLabel": "Payjoin",
   "receivePayjoinAwaitingFunds": "Payjoin-ը միացված է, սակայն այս դրամապանակը դեռ ներդրման համար մնացորդ չունի։ Այն կակտիվանա միջոցներ ստանալուն պես։",
-  "announcementAutoswapDescription": "Ձեր Liquid-ը ավտոմատ փոխանակվում է Bitcoin-ի։"
+  "announcementAutoswapDescription": "Ձեր Liquid-ը ավտոմատ փոխանակվում է Bitcoin-ի։",
+  "legacySeedViewErrorFetch": "Չհաջողվեց բեռնել հին սերմերը։ Խնդրում ենք կրկին փորձել։"
 }