refactor(ledger): align the failure family with the #1895 standard

Four points where the ledger implementation drifted from the standard in #2293:

The failure family moves to domain/ and the exception family to data/, matching
the layer each word belongs to — a Failure is a domain value, an Exception is
thrown infra.

The catch-all now returns the shared oopsSomethingWentWrong instead of a
ledger-specific "unknown error" string, so the redundant key is gone from all
27 locales.

ConnectionTypeNotInitialized no longer maps to the generic failure. The
transports are nullable and initialized during scan, so this fires on a
reachable path and means "no connection available" — which is actionable,
unlike "Oops, something went wrong".

The APDU status word is only read when it is labelled (0x6985, sw=6985). The
previous pattern matched any four hex-ish characters, so "timeout after 6985
ms" was reported to the user as "you rejected the operation on the device".

Also drops the last `dynamic` from the operation seam and closes the repository
contract with `abstract interface class`.

Author: wired-pasteque

lib/core/ledger/data/datasources/ledger_device_datasource.dart

@@ -4,7 +4,7 @@ import 'dart:io';
 import 'package:bb_mobile/core/entities/signer_device_entity.dart';
 import 'package:bb_mobile/core/ledger/data/models/ledger_device_model.dart';
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_exception.dart';
+import 'package:bb_mobile/core/ledger/data/ledger_exception.dart';
 import 'package:bb_mobile/core/utils/logger.dart';
 import 'package:bb_mobile/core/wallet/domain/entities/wallet.dart';
 import 'package:bull_sdk/bdk.dart' as bdk;

…dger/domain/errors/ledger_exception.dart …b/core/ledger/data/ledger_exception.dartlib/core/ledger/domain/errors/ledger_exception.dart renamed to lib/core/ledger/data/ledger_exception.dart lib/core/ledger/domain/errors/ledger_exception.dart renamed to lib/core/ledger/data/ledger_exception.dart

@@ -2,8 +2,8 @@ import 'package:bb_mobile/core/entities/signer_device_entity.dart';
 import 'package:bb_mobile/core/ledger/data/datasources/ledger_device_datasource.dart';
 import 'package:bb_mobile/core/ledger/data/models/ledger_device_model.dart';
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_exception.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/data/ledger_exception.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/utils/logger.dart';
 import 'package:bb_mobile/core/utils/result.dart';
@@ -128,9 +128,12 @@ class LedgerDeviceRepositoryImpl implements LedgerDeviceRepository {
     } on InvalidMagicBytesLedgerException {
       return const Err(LedgerInvalidPsbtFailure());
     } on ConnectionTypeNotInitializedLedgerException {
-      // Internal wiring bug — never a meaningful message for the user.
+      // The transport for this device was never initialized (its scan did not
+      // run or did not complete), so there is nothing to talk to. That is the
+      // same situation as a missing connection from the user's point of view —
+      // and "no connection available" is actionable, unlike a generic "oops".
       return const Err(
-        LedgerUnexpectedFailure('connection type not initialized'),
+        LedgerNoConnectionFailure('connection type not initialized'),
       );
     } catch (e, st) {
       final failure = _interpretRawError(e);
@@ -171,16 +174,22 @@ class LedgerDeviceRepositoryImpl implements LedgerDeviceRepository {
   );
 
   /// Extracts a normalized (lowercase, no `0x`) 4-hex-digit APDU status word.
-  /// Matches are anchored on word boundaries and accept an optional `0x`
-  /// prefix, so a status word survives but an incidental 4-hex run inside a
-  /// txid/address does not get mistaken for one.
   String? _extractApduCode(String error) {
     final match = _apduCodePattern.firstMatch(error);
-    return match?.group(1)?.toLowerCase();
+    if (match == null) return null;
+    return (match.group(1) ?? match.group(2))?.toLowerCase();
   }
 
+  /// Matches an APDU status word only when it is unambiguously labelled: either
+  /// hex-prefixed (`0x6985`) or introduced by a status-word keyword (`sw=6985`,
+  /// `status word 6985`, `apdu: 6985`). A bare 4-character run is deliberately
+  /// NOT matched — `timeout after 6985 ms`, or an incidental slice of a txid,
+  /// would otherwise be read as "rejected by user" and show the user a
+  /// confidently wrong reason.
   static final RegExp _apduCodePattern = RegExp(
-    r'\b(?:0x)?([0-9a-f]{4})\b',
+    r'0x([0-9a-f]{4})\b'
+    r'|\b(?:sw|status(?:\s*word)?|apdu(?:\s*(?:code|status))?|code)'
+    r'\s*[:=]?\s*(?:0x)?([0-9a-f]{4})\b',
     caseSensitive: false,
   );
 }

lib/core/ledger/data/repositories/ledger_device_repository_impl.dart

@@ -1,11 +1,5 @@
 import 'package:bb_mobile/core/failures/failure.dart';
 
-/// Closed set of every failure the ledger domain surfaces to the user.
-/// `sealed` keeps it closed (exhaustive switches; no foreign variants). Pure
-/// Dart — the user-facing message lives in the presentation extension
-/// `ledger_failure_l10n.dart`, never here. The raw device/SDK reason is logged
-/// at the repository boundary and, when kept at all, lives only in
-/// [Failure.logMessage] for logs/Sentry.
 sealed class LedgerFailure extends Failure {
   const LedgerFailure([super.logMessage]);
 }

…ledger/domain/errors/ledger_failure.dart …b/core/ledger/domain/ledger_failure.dartlib/core/ledger/domain/errors/ledger_failure.dart renamed to lib/core/ledger/domain/ledger_failure.dart lib/core/ledger/domain/errors/ledger_failure.dart renamed to lib/core/ledger/domain/ledger_failure.dart

@@ -1,11 +1,11 @@
 import 'package:bb_mobile/core/entities/signer_device_entity.dart';
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/utils/result.dart';
 import 'package:bb_mobile/core/wallet/domain/entities/wallet.dart';
 import 'package:meta/meta.dart';
 
-abstract class LedgerDeviceRepository {
+abstract interface class LedgerDeviceRepository {
   @useResult
   Future<Result<List<LedgerDeviceEntity>, LedgerFailure>> scanDevices({
     SignerDeviceEntity? deviceType,

lib/core/ledger/domain/repositories/ledger_device_repository.dart

@@ -1,5 +1,5 @@
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/utils/result.dart';
 import 'package:meta/meta.dart';

lib/core/ledger/domain/usecases/connect_ledger_device_usecase.dart

@@ -1,6 +1,6 @@
 import 'package:bb_mobile/core/entities/signer_entity.dart';
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/settings/data/settings_repository.dart';
 import 'package:bb_mobile/core/utils/result.dart';

lib/core/ledger/domain/usecases/get_ledger_watch_only_wallet_usecase.dart

@@ -1,6 +1,6 @@
 import 'package:bb_mobile/core/entities/signer_device_entity.dart';
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/utils/result.dart';
 import 'package:meta/meta.dart';

lib/core/ledger/domain/usecases/scan_ledger_devices_usecase.dart

@@ -1,5 +1,5 @@
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/utils/result.dart';
 import 'package:bb_mobile/core/wallet/domain/entities/wallet.dart';

lib/core/ledger/domain/usecases/sign_psbt_ledger_usecase.dart

@@ -1,5 +1,5 @@
 import 'package:bb_mobile/core/ledger/domain/entities/ledger_device_entity.dart';
-import 'package:bb_mobile/core/ledger/domain/errors/ledger_failure.dart';
+import 'package:bb_mobile/core/ledger/domain/ledger_failure.dart';
 import 'package:bb_mobile/core/ledger/domain/repositories/ledger_device_repository.dart';
 import 'package:bb_mobile/core/utils/result.dart';
 import 'package:bb_mobile/core/wallet/domain/entities/wallet.dart';