fix(labels): stop leaking raw error detail in label messages

LabelError becomes a sealed family with per-variant toTranslated. The unexpected catch-all now returns a generic localized message instead of the raw exception text, and the label usecases log the technical reason at the mapping site.

Author: ethicnology

lib/features/labels/application/usecases/fetch_all_labels_usecase.dart

@@ -17,9 +17,11 @@ class FetchAllLabelsUsecase {
           .toList();
     } on LabelError {
       rethrow;
-    } catch (e) {
-      log.severe(error: e, trace: StackTrace.current);
-      throw LabelError.unexpected('Failed to fetch all labels: $e');
+    } catch (e, st) {
+      // Keep the technical reason in the logs; the UI maps the unexpected
+      // variant to a generic message and never shows [e].
+      log.severe(message: 'Failed to fetch all labels', error: e, trace: st);
+      throw UnexpectedLabelError('Failed to fetch all labels: $e');
     }
   }
 }

lib/features/labels/application/usecases/fetch_label_by_reference_usecase.dart

@@ -1,3 +1,4 @@
+import 'package:bb_mobile/core/utils/logger.dart';
 import 'package:bb_mobile/features/labels/adapters/label_mapper.dart';
 import 'package:bb_mobile/features/labels/application/application_label.dart';
 import 'package:bb_mobile/features/labels/application/labels_repository_port.dart';
@@ -16,10 +17,13 @@ class FetchLabelByReferenceUsecase {
           .toList();
     } on LabelError {
       rethrow;
-    } catch (e) {
-      throw LabelError.unexpected(
-        'Failed to fetch label for reference $reference: $e',
-      );
+    } catch (e, st) {
+      // Keep the technical reason in the logs; the UI maps the unexpected
+      // variant to a generic message and never shows [e]. The reference is a
+      // txid/address/xpub — keep it OUT of the Sentry-bound message to avoid
+      // leaking an on-chain identifier off-device.
+      log.severe(message: 'Failed to fetch label by reference', error: e, trace: st);
+      throw UnexpectedLabelError('Failed to fetch label by reference: $e');
     }
   }
 }

lib/features/labels/application/usecases/store_labels_usecase.dart

@@ -1,3 +1,4 @@
+import 'package:bb_mobile/core/utils/logger.dart';
 import 'package:bb_mobile/features/labels/adapters/label_mapper.dart';
 import 'package:bb_mobile/features/labels/application/application_label.dart';
 import 'package:bb_mobile/features/labels/application/labels_repository_port.dart';
@@ -22,8 +23,11 @@ class StoreLabelUsecase {
       return LabelMapper.labelEntityToApplicationLabel(storedLabel);
     } on LabelError {
       rethrow;
-    } catch (e) {
-      throw LabelError.unexpected('Failed to batch labels: $e');
+    } catch (e, st) {
+      // Keep the technical reason in the logs; the UI maps the unexpected
+      // variant to a generic message and never shows [e].
+      log.severe(message: 'Failed to store label', error: e, trace: st);
+      throw UnexpectedLabelError('Failed to store label: $e');
     }
   }
 }

lib/features/labels/application/usecases/trash_label_usecase.dart

@@ -1,3 +1,4 @@
+import 'package:bb_mobile/core/utils/logger.dart';
 import 'package:bb_mobile/features/labels/application/labels_repository_port.dart';
 import 'package:bb_mobile/features/labels/domain/label_error.dart';
 
@@ -11,8 +12,11 @@ class TrashLabelUsecase {
       await _labelRepository.trash(id);
     } on LabelError {
       rethrow;
-    } catch (e) {
-      throw LabelError.unexpected('Failed to trash label $id: $e');
+    } catch (e, st) {
+      // Keep the technical reason in the logs; the UI maps the unexpected
+      // variant to a generic message and never shows [e].
+      log.severe(message: 'Failed to trash label $id', error: e, trace: st);
+      throw UnexpectedLabelError('Failed to trash label $id: $e');
     }
   }
 }

lib/features/labels/domain/label_error.dart

@@ -1,14 +1,51 @@
-import 'package:freezed_annotation/freezed_annotation.dart';
-
-part 'label_error.freezed.dart';
-
-@freezed
-sealed class LabelError with _$LabelError {
-  const factory LabelError.notFound({required String label}) = LabelNotFound;
-  const factory LabelError.unsupportedType(Type runtimeType) =
-      UnsupportedLabelType;
-  const factory LabelError.unexpected(String? message) = UnexpectedLabelError;
-  const factory LabelError.systemLabelCannotBeDeleted() =
-      SystemLabelCannotBeDeletedError;
-  const LabelError._();
+import 'package:bb_mobile/core/utils/build_context_x.dart';
+import 'package:flutter/widgets.dart';
+
+/// Closed set of every failure the labels feature surfaces to the user.
+/// `sealed` keeps it closed (no foreign variants; exhaustive switches). The
+/// abstract `toTranslated` makes a user-facing message mandatory and keeps it
+/// next to its variant.
+sealed class LabelError {
+  const LabelError();
+
+  /// Localized, user-safe message. Never returns raw/technical detail.
+  String toTranslated(BuildContext context);
+}
+
+final class LabelNotFound extends LabelError {
+  final String label;
+
+  const LabelNotFound({required this.label});
+
+  @override
+  String toTranslated(BuildContext context) =>
+      context.loc.labelErrorNotFound(label);
+}
+
+final class UnsupportedLabelType extends LabelError {
+  const UnsupportedLabelType();
+
+  @override
+  String toTranslated(BuildContext context) =>
+      context.loc.labelErrorUnsupportedType;
+}
+
+final class SystemLabelCannotBeDeletedError extends LabelError {
+  const SystemLabelCannotBeDeletedError();
+
+  @override
+  String toTranslated(BuildContext context) =>
+      context.loc.labelErrorSystemCannotDelete;
+}
+
+/// Catch-all. [message] is for logs only and MUST never reach the UI —
+/// `toTranslated` returns the shared generic string, not [message].
+final class UnexpectedLabelError extends LabelError {
+  final String? message;
+
+  const UnexpectedLabelError(this.message);
+
+  @override
+  String toTranslated(BuildContext context) =>
+      context.loc.oopsSomethingWentWrong;
 }

lib/features/labels/ui/labels_widget.dart

@@ -7,17 +7,6 @@ import 'package:bb_mobile/features/labels/labels_facade.dart';
 import 'package:bb_mobile/locator.dart';
 import 'package:flutter/material.dart';
 
-extension LabelErrorTranslation on LabelError {
-  String toTranslated(BuildContext context) => when(
-    notFound: (label) => context.loc.labelErrorNotFound(label),
-    unsupportedType: (type) =>
-        context.loc.labelErrorUnsupportedType(type.toString()),
-    unexpected: (message) =>
-        message != null ? context.loc.labelErrorUnexpected(message) : '',
-    systemLabelCannotBeDeleted: () => context.loc.labelErrorSystemCannotDelete,
-  );
-}
-
 class LabelsWidget extends StatefulWidget {
   const LabelsWidget({super.key, required this.labels, this.onDelete});