Merge pull request 'feat(catalog): Katalogsuche in der App (KAT-01, 3b App)' (#63) from feature/3b-katalog-suche-app into main

Reviewed-on: #63

app/lib/core/logging/app_logger.dart

@@ -48,7 +48,17 @@ class AppLogger {
     _subscription = null;
   }
 
+  /// Whether a record is written. Records of the Supabase libraries below
+  /// INFO are dropped: postgrest logs `'$error from request'` at FINE, and the
+  /// error text can echo request parameters (search terms, QUE-04).
+  @visibleForTesting
+  static bool shouldWrite(LogRecord record) =>
+      !(record.loggerName.startsWith('supabase') && record.level < Level.INFO);
+
   static void _write(LogRecord record) {
+    if (!shouldWrite(record)) {
+      return;
+    }
     developer.log(
       record.message,
       time: record.time,

app/lib/core/routing/app_router.dart

@@ -5,6 +5,7 @@ import 'package:shuffle/core/routing/not_found_screen.dart';
 import 'package:shuffle/core/routing/redirect_source.dart';
 import 'package:shuffle/core/routing/volatile_extra_codec.dart';
 import 'package:shuffle/features/auth/presentation/auth_routes.dart';
+import 'package:shuffle/features/catalog/presentation/catalog_routes.dart';
 import 'package:shuffle/features/home/presentation/home_screen.dart';
 
 part 'app_router.g.dart';
@@ -23,6 +24,7 @@ GoRouter appRouter(Ref ref) {
       GoRoute(
         path: AppRoutes.home,
         builder: (context, state) => const HomeScreen(),
+        routes: catalogRoutes,
       ),
       ...authRoutes,
     ],

app/lib/core/routing/app_router.g.dart

@@ -48,4 +48,4 @@ final class AppRouterProvider
   }
 }
 
-String _$appRouterHash() => r'39ea53d71fba02f9e9cc5e42df61144e55eca3d9';
+String _$appRouterHash() => r'cb20752ab64cf1ac56d3bfce5401e187246f5ec7';

app/lib/core/routing/app_routes.dart

@@ -2,6 +2,12 @@
 abstract final class AppRoutes {
   static const home = '/';
 
+  /// Katalogsuche, öffentlich (Spec #3 § 5.5).
+  static const catalog = '/catalog';
+
+  /// Segment of [catalog] below [home] (nested route).
+  static const catalogSegment = 'catalog';
+
   // Auth (Spec #1 § 5.3)
   static const login = '/login';
   static const register = '/register';

app/lib/core/routing/url_replacer.dart

@@ -0,0 +1,41 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
+import 'package:go_router/go_router.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'url_replacer.g.dart';
+
+/// Replaces the browser URL of the current page without a new history entry
+/// and without rebuilding the page (so state, scroll position and focus stay).
+///
+/// Web only: on other platforms there is no visible URL, nothing happens.
+/// The router state is updated inside `Router.neglect` (no history entry from
+/// the router), the address bar is replaced with
+/// `SystemNavigator.routeInformationUpdated(replace: true)`.
+class UrlReplacer {
+  const UrlReplacer({this.isWeb = kIsWeb});
+
+  /// Whether to write at all (injectable for tests).
+  final bool isWeb;
+
+  void replace(BuildContext context, Uri uri) {
+    if (!isWeb) {
+      return;
+    }
+    final router = GoRouter.maybeOf(context);
+    if (router != null) {
+      final current = router.routeInformationProvider.value.uri;
+      if (current != uri) {
+        Router.neglect(context, () => router.go(uri.toString()));
+      }
+    }
+    unawaited(SystemNavigator.routeInformationUpdated(uri: uri, replace: true));
+  }
+}
+
+/// Override in tests.
+@Riverpod(keepAlive: true)
+UrlReplacer urlReplacer(Ref ref) => const UrlReplacer();

app/lib/core/routing/url_replacer.g.dart

@@ -0,0 +1,55 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'url_replacer.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint, type=warning
+/// Override in tests.
+
+@ProviderFor(urlReplacer)
+final urlReplacerProvider = UrlReplacerProvider._();
+
+/// Override in tests.
+
+final class UrlReplacerProvider
+    extends $FunctionalProvider<UrlReplacer, UrlReplacer, UrlReplacer>
+    with $Provider<UrlReplacer> {
+  /// Override in tests.
+  UrlReplacerProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: null,
+        name: r'urlReplacerProvider',
+        isAutoDispose: false,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$urlReplacerHash();
+
+  @$internal
+  @override
+  $ProviderElement<UrlReplacer> $createElement($ProviderPointer pointer) =>
+      $ProviderElement(pointer);
+
+  @override
+  UrlReplacer create(Ref ref) {
+    return urlReplacer(ref);
+  }
+
+  /// {@macro riverpod.override_with_value}
+  Override overrideWithValue(UrlReplacer value) {
+    return $ProviderOverride(
+      origin: this,
+      providerOverride: $SyncValueProvider<UrlReplacer>(value),
+    );
+  }
+}
+
+String _$urlReplacerHash() => r'84773dd072e19ea69ca1b6438f9f7f5dea7f44d9';

app/lib/core/widgets/app_list_footer.dart

@@ -0,0 +1,88 @@
+import 'package:flutter/material.dart';
+import 'package:shuffle/core/theme/app_spacing.dart';
+
+/// Footer of a paged list: loading indicator, "load more" button or an error
+/// with retry (QUE-06 criterion 4: the button is reachable by keyboard and
+/// screen reader, auto-loading is only a convenience).
+///
+/// Priority: [errorMessage] over [isLoading] over [hasMore]. Already loaded
+/// items stay in the list in every case. All strings come from the caller.
+class AppListFooter extends StatelessWidget {
+  const AppListFooter({
+    required this.isLoading,
+    required this.hasMore,
+    required this.loadingLabel,
+    required this.loadMoreLabel,
+    required this.retryLabel,
+    required this.onLoadMore,
+    required this.onRetry,
+    super.key,
+    this.errorMessage,
+  });
+
+  final bool isLoading;
+  final bool hasMore;
+  final String? errorMessage;
+
+  /// Spoken label of the progress indicator.
+  final String loadingLabel;
+  final String loadMoreLabel;
+  final String retryLabel;
+  final VoidCallback onLoadMore;
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    final message = errorMessage;
+    final Widget content;
+    if (message != null) {
+      content = Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Semantics(
+            container: true,
+            liveRegion: true,
+            child: Text(
+              message,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodyMedium
+                  ?.copyWith(color: Theme.of(context).colorScheme.error),
+            ),
+          ),
+          const SizedBox(height: AppSpacing.sm),
+          OutlinedButton(
+            key: const Key('list_footer_retry'),
+            onPressed: onRetry,
+            child: Text(retryLabel),
+          ),
+        ],
+      );
+    } else if (isLoading) {
+      content = Semantics(
+        label: loadingLabel,
+        liveRegion: true,
+        child: const SizedBox(
+          key: Key('list_footer_loading'),
+          width: AppSpacing.xxxl,
+          height: AppSpacing.xxxl,
+          child: Padding(
+            padding: EdgeInsets.all(AppSpacing.md),
+            child: CircularProgressIndicator(strokeWidth: 3),
+          ),
+        ),
+      );
+    } else if (hasMore) {
+      content = OutlinedButton(
+        key: const Key('list_footer_load_more'),
+        onPressed: onLoadMore,
+        child: Text(loadMoreLabel),
+      );
+    } else {
+      return const SizedBox(height: AppSpacing.lg);
+    }
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: AppSpacing.lg),
+      child: Center(child: content),
+    );
+  }
+}

app/lib/core/widgets/app_state_message.dart

@@ -0,0 +1,100 @@
+import 'package:flutter/material.dart';
+import 'package:shuffle/core/theme/app_spacing.dart';
+
+/// An action button of [AppStateMessage].
+class AppStateAction {
+  const AppStateAction({
+    required this.label,
+    required this.onPressed,
+    this.key,
+  });
+
+  final String label;
+  final VoidCallback onPressed;
+  final Key? key;
+}
+
+/// Message for an empty or failed list: icon, title, optional hint and
+/// optional actions (48 dp buttons).
+///
+/// The text is a live region, so screen readers announce it when it appears
+/// after a search. All strings come from the caller (l10n). The icon is
+/// decorative and hidden from screen readers.
+class AppStateMessage extends StatelessWidget {
+  const AppStateMessage({
+    required this.icon,
+    required this.title,
+    super.key,
+    this.message,
+    this.actions = const [],
+  });
+
+  final IconData icon;
+  final String title;
+  final String? message;
+
+  /// The first action is emphasized (tonal), the others are outlined.
+  final List<AppStateAction> actions;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final scheme = theme.colorScheme;
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(AppSpacing.xl),
+        child: ConstrainedBox(
+          constraints: const BoxConstraints(maxWidth: 420),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              ExcludeSemantics(
+                child: Icon(icon, size: 48, color: scheme.onSurfaceVariant),
+              ),
+              const SizedBox(height: AppSpacing.lg),
+              Semantics(
+                container: true,
+                liveRegion: true,
+                child: Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    Text(
+                      title,
+                      textAlign: TextAlign.center,
+                      style: theme.textTheme.titleMedium,
+                    ),
+                    if (message != null) ...[
+                      const SizedBox(height: AppSpacing.sm),
+                      Text(
+                        message!,
+                        textAlign: TextAlign.center,
+                        style: theme.textTheme.bodyMedium?.copyWith(
+                          color: scheme.onSurfaceVariant,
+                        ),
+                      ),
+                    ],
+                  ],
+                ),
+              ),
+              if (actions.isNotEmpty) const SizedBox(height: AppSpacing.lg),
+              for (var i = 0; i < actions.length; i++) ...[
+                if (i > 0) const SizedBox(height: AppSpacing.sm),
+                i == 0
+                    ? FilledButton.tonal(
+                        key: actions[i].key,
+                        onPressed: actions[i].onPressed,
+                        child: Text(actions[i].label),
+                      )
+                    : OutlinedButton(
+                        key: actions[i].key,
+                        onPressed: actions[i].onPressed,
+                        child: Text(actions[i].label),
+                      ),
+              ],
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}

app/lib/features/catalog/data/catalog_failure_mapper.dart

@@ -0,0 +1,24 @@
+import 'dart:async';
+
+import 'package:http/http.dart' as http;
+import 'package:shuffle/core/platform/io_error.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:supabase_flutter/supabase_flutter.dart';
+
+const _invalidInputCodes = {'P0001', '22003', '22P02'};
+
+/// Translates exceptions of `supabase_flutter` into a [CatalogFailure]
+/// (Spec #3 § 5.2).
+CatalogFailure mapCatalogError(Object error) {
+  if (error is TimeoutException ||
+      error is http.ClientException ||
+      isIoNetworkError(error)) {
+    return const CatalogFailure.network();
+  }
+  // P0001: RPC input checks; 22003: number out of range (smallint cast);
+  // 22P02: invalid text representation. None gets better by repeating.
+  if (error is PostgrestException && _invalidInputCodes.contains(error.code)) {
+    return const CatalogFailure.invalidInput();
+  }
+  return const CatalogFailure.unexpected();
+}

app/lib/features/catalog/data/catalog_game_summary_dto.dart

@@ -0,0 +1,57 @@
+import 'package:json_annotation/json_annotation.dart';
+import 'package:shuffle/features/catalog/domain/catalog_game_summary.dart';
+
+part 'catalog_game_summary_dto.g.dart';
+
+/// One row of `search_catalog_games` (Spec #3 § 4.2). Read only: no `toJson`.
+///
+/// `total_count` and `match_rank` are not part of the DTO; the repository
+/// reads the total from the first row and the app does not show the rank.
+@JsonSerializable(createToJson: false, fieldRename: FieldRename.snake)
+class CatalogGameSummaryDto {
+  const CatalogGameSummaryDto({
+    required this.id,
+    required this.title,
+    required this.publisherNames,
+    this.year,
+    this.minPlayers,
+    this.maxPlayers,
+    this.minMinutes,
+    this.maxMinutes,
+    this.minAge,
+    this.imagePath,
+    this.matchedAltTitle,
+  });
+
+  factory CatalogGameSummaryDto.fromJson(Map<String, dynamic> json) =>
+      _$CatalogGameSummaryDtoFromJson(json);
+
+  final String id;
+  final String title;
+  final int? year;
+  final int? minPlayers;
+  final int? maxPlayers;
+  final int? minMinutes;
+  final int? maxMinutes;
+  final int? minAge;
+  final String? imagePath;
+
+  /// The backend sends an empty array instead of `null`; be lenient anyway.
+  @JsonKey(defaultValue: <String>[])
+  final List<String> publisherNames;
+  final String? matchedAltTitle;
+
+  CatalogGameSummary toDomain() => CatalogGameSummary(
+    id: id,
+    title: title,
+    year: year,
+    minPlayers: minPlayers,
+    maxPlayers: maxPlayers,
+    minMinutes: minMinutes,
+    maxMinutes: maxMinutes,
+    minAge: minAge,
+    imagePath: imagePath,
+    publisherNames: publisherNames,
+    matchedAltTitle: matchedAltTitle,
+  );
+}

app/lib/features/catalog/data/catalog_game_summary_dto.g.dart

@@ -0,0 +1,27 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'catalog_game_summary_dto.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+CatalogGameSummaryDto _$CatalogGameSummaryDtoFromJson(
+  Map<String, dynamic> json,
+) => CatalogGameSummaryDto(
+  id: json['id'] as String,
+  title: json['title'] as String,
+  publisherNames:
+      (json['publisher_names'] as List<dynamic>?)
+          ?.map((e) => e as String)
+          .toList() ??
+      [],
+  year: (json['year'] as num?)?.toInt(),
+  minPlayers: (json['min_players'] as num?)?.toInt(),
+  maxPlayers: (json['max_players'] as num?)?.toInt(),
+  minMinutes: (json['min_minutes'] as num?)?.toInt(),
+  maxMinutes: (json['max_minutes'] as num?)?.toInt(),
+  minAge: (json['min_age'] as num?)?.toInt(),
+  imagePath: json['image_path'] as String?,
+  matchedAltTitle: json['matched_alt_title'] as String?,
+);

app/lib/features/catalog/data/catalog_term_dto.dart

@@ -0,0 +1,23 @@
+import 'package:json_annotation/json_annotation.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+
+part 'catalog_term_dto.g.dart';
+
+/// One row of `genres` or `mechanics`. Read only: no `toJson`.
+@JsonSerializable(createToJson: false, fieldRename: FieldRename.snake)
+class CatalogTermDto {
+  const CatalogTermDto({
+    required this.id,
+    required this.nameDe,
+    required this.nameEn,
+  });
+
+  factory CatalogTermDto.fromJson(Map<String, dynamic> json) =>
+      _$CatalogTermDtoFromJson(json);
+
+  final String id;
+  final String nameDe;
+  final String nameEn;
+
+  CatalogTerm toDomain() => CatalogTerm(id: id, nameDe: nameDe, nameEn: nameEn);
+}

app/lib/features/catalog/data/catalog_term_dto.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'catalog_term_dto.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+CatalogTermDto _$CatalogTermDtoFromJson(Map<String, dynamic> json) =>
+    CatalogTermDto(
+      id: json['id'] as String,
+      nameDe: json['name_de'] as String,
+      nameEn: json['name_en'] as String,
+    );

app/lib/features/catalog/data/supabase_catalog_repository.dart

@@ -0,0 +1,116 @@
+import 'dart:async';
+
+import 'package:shuffle/core/logging/app_logger.dart';
+import 'package:shuffle/core/result/result.dart';
+import 'package:shuffle/features/catalog/data/catalog_failure_mapper.dart';
+import 'package:shuffle/features/catalog/data/catalog_game_summary_dto.dart';
+import 'package:shuffle/features/catalog/data/catalog_term_dto.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_repository.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_page.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+import 'package:supabase_flutter/supabase_flutter.dart';
+
+final _log = AppLogger('CatalogRepository');
+
+/// [CatalogRepository] against Supabase: the RPC `search_catalog_games`
+/// (contract: Spec #3 § 4.2) and the vocabulary tables.
+///
+/// Read only. Privacy (QUE-04): errors are logged by kind only, never with the
+/// search text or the exception message (which could echo the parameters).
+class SupabaseCatalogRepository implements CatalogRepository {
+  SupabaseCatalogRepository(
+    this._client, {
+    this.timeout = const Duration(seconds: 10),
+  });
+
+  final SupabaseClient _client;
+
+  /// Time limit per call.
+  final Duration timeout;
+
+  /// Builds the RPC parameters from set values only (Spec #3 § 5.2): no
+  /// `null` for empty sets, no search text below the minimum length.
+  static Map<String, dynamic> buildSearchParams(
+    CatalogSearchQuery query, {
+    required int offset,
+    required int limit,
+  }) {
+    final effective = query.effective;
+    final filters = effective.filters;
+    return {
+      if (effective.hasText) 'p_query': effective.text,
+      'p_players': ?filters.players,
+      'p_max_minutes': ?filters.maxMinutes,
+      'p_age': ?filters.minAgeSuitable,
+      if (filters.genreIds.isNotEmpty)
+        'p_genre_ids': filters.genreIds.toList(growable: false),
+      if (filters.mechanicIds.isNotEmpty)
+        'p_mechanic_ids': filters.mechanicIds.toList(growable: false),
+      'p_limit': limit,
+      'p_offset': offset,
+    };
+  }
+
+  @override
+  Future<Result<CatalogSearchPage, CatalogFailure>> search(
+    CatalogSearchQuery query, {
+    required int offset,
+    int limit = CatalogSearchLimits.pageSize,
+  }) async {
+    try {
+      final params = buildSearchParams(query, offset: offset, limit: limit);
+      final response = await _client
+          .rpc<dynamic>('search_catalog_games', params: params)
+          .timeout(timeout);
+      final rows = (response as List<dynamic>).cast<Map<String, dynamic>>();
+      final items = [
+        for (final row in rows) CatalogGameSummaryDto.fromJson(row).toDomain(),
+      ];
+      final total = rows.isEmpty ? 0 : (rows.first['total_count'] as num);
+      return Result.success(
+        CatalogSearchPage(items: items, totalCount: total.toInt()),
+      );
+    } on Object catch (error) {
+      return Result.failure(_fail('search', error));
+    }
+  }
+
+  @override
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchGenres() =>
+      _fetchTerms('genres');
+
+  @override
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchMechanics() =>
+      _fetchTerms('mechanics');
+
+  Future<Result<List<CatalogTerm>, CatalogFailure>> _fetchTerms(
+    String table,
+  ) async {
+    try {
+      final rows = await _client
+          .from(table)
+          .select('id, name_de, name_en')
+          .timeout(timeout);
+      return Result.success([
+        for (final row in rows) CatalogTermDto.fromJson(row).toDomain(),
+      ]);
+    } on Object catch (error) {
+      return Result.failure(_fail(table, error));
+    }
+  }
+
+  /// Maps and logs an error. Logs the failure kind only.
+  CatalogFailure _fail(String operation, Object error) {
+    final failure = mapCatalogError(error);
+    // Stable names (runtime type names are minified on the web).
+    final kind = switch (failure) {
+      CatalogNetworkFailure() => 'network',
+      CatalogInvalidInputFailure() => 'invalidInput',
+      CatalogUnexpectedFailure() => 'unexpected',
+    };
+    _log.warning('Catalog $operation failed: $kind');
+    return failure;
+  }
+}

app/lib/features/catalog/domain/catalog_failure.dart

@@ -0,0 +1,16 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'catalog_failure.freezed.dart';
+
+/// Expected failures of catalog calls (Spec #3 § 5.2).
+@freezed
+sealed class CatalogFailure with _$CatalogFailure {
+  /// No connection or timeout.
+  const factory CatalogFailure.network() = CatalogNetworkFailure;
+
+  /// The backend rejected the input (`P0001`). The app prevents this at input
+  /// time, so it is a programming error.
+  const factory CatalogFailure.invalidInput() = CatalogInvalidInputFailure;
+
+  const factory CatalogFailure.unexpected() = CatalogUnexpectedFailure;
+}

app/lib/features/catalog/domain/catalog_failure.freezed.dart

@@ -0,0 +1,277 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_failure.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogFailure {
+
+
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogFailure);
+}
+
+
+@override
+int get hashCode => runtimeType.hashCode;
+
+@override
+String toString() {
+    return 'CatalogFailure()';
+}
+
+
+}
+
+/// @nodoc
+class $CatalogFailureCopyWith<$Res>  {
+$CatalogFailureCopyWith(CatalogFailure _, $Res Function(CatalogFailure) __);
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogFailure].
+extension CatalogFailurePatterns on CatalogFailure {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>({TResult Function( CatalogNetworkFailure value)?  network,TResult Function( CatalogInvalidInputFailure value)?  invalidInput,TResult Function( CatalogUnexpectedFailure value)?  unexpected,required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case CatalogNetworkFailure() when network != null:
+return network(_that);case CatalogInvalidInputFailure() when invalidInput != null:
+return invalidInput(_that);case CatalogUnexpectedFailure() when unexpected != null:
+return unexpected(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>({required TResult Function( CatalogNetworkFailure value)  network,required TResult Function( CatalogInvalidInputFailure value)  invalidInput,required TResult Function( CatalogUnexpectedFailure value)  unexpected,}){
+final _that = this;
+switch (_that) {
+case CatalogNetworkFailure():
+return network(_that);case CatalogInvalidInputFailure():
+return invalidInput(_that);case CatalogUnexpectedFailure():
+return unexpected(_that);}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>({TResult? Function( CatalogNetworkFailure value)?  network,TResult? Function( CatalogInvalidInputFailure value)?  invalidInput,TResult? Function( CatalogUnexpectedFailure value)?  unexpected,}){
+final _that = this;
+switch (_that) {
+case CatalogNetworkFailure() when network != null:
+return network(_that);case CatalogInvalidInputFailure() when invalidInput != null:
+return invalidInput(_that);case CatalogUnexpectedFailure() when unexpected != null:
+return unexpected(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>({TResult Function()?  network,TResult Function()?  invalidInput,TResult Function()?  unexpected,required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case CatalogNetworkFailure() when network != null:
+return network();case CatalogInvalidInputFailure() when invalidInput != null:
+return invalidInput();case CatalogUnexpectedFailure() when unexpected != null:
+return unexpected();case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>({required TResult Function()  network,required TResult Function()  invalidInput,required TResult Function()  unexpected,}) {final _that = this;
+switch (_that) {
+case CatalogNetworkFailure():
+return network();case CatalogInvalidInputFailure():
+return invalidInput();case CatalogUnexpectedFailure():
+return unexpected();}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>({TResult? Function()?  network,TResult? Function()?  invalidInput,TResult? Function()?  unexpected,}) {final _that = this;
+switch (_that) {
+case CatalogNetworkFailure() when network != null:
+return network();case CatalogInvalidInputFailure() when invalidInput != null:
+return invalidInput();case CatalogUnexpectedFailure() when unexpected != null:
+return unexpected();case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class CatalogNetworkFailure implements CatalogFailure {
+  const CatalogNetworkFailure();
+  
+
+
+
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogNetworkFailure);
+}
+
+
+@override
+int get hashCode => runtimeType.hashCode;
+
+@override
+String toString() {
+    return 'CatalogFailure.network()';
+}
+
+
+}
+
+
+
+
+/// @nodoc
+
+
+class CatalogInvalidInputFailure implements CatalogFailure {
+  const CatalogInvalidInputFailure();
+  
+
+
+
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogInvalidInputFailure);
+}
+
+
+@override
+int get hashCode => runtimeType.hashCode;
+
+@override
+String toString() {
+    return 'CatalogFailure.invalidInput()';
+}
+
+
+}
+
+
+
+
+/// @nodoc
+
+
+class CatalogUnexpectedFailure implements CatalogFailure {
+  const CatalogUnexpectedFailure();
+  
+
+
+
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogUnexpectedFailure);
+}
+
+
+@override
+int get hashCode => runtimeType.hashCode;
+
+@override
+String toString() {
+    return 'CatalogFailure.unexpected()';
+}
+
+
+}
+
+
+
+
+// dart format on

app/lib/features/catalog/domain/catalog_game_summary.dart

@@ -0,0 +1,30 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'catalog_game_summary.freezed.dart';
+
+/// A catalog game as shown in a result list (Spec #3 § 5.2).
+///
+/// Read only: there is intentionally no JSON conversion, nothing here is ever
+/// written back to the database. The detail model `CatalogGame` comes with
+/// KAT-02 (#4).
+@freezed
+abstract class CatalogGameSummary with _$CatalogGameSummary {
+  const factory CatalogGameSummary({
+    required String id,
+    required String title,
+    int? year,
+    int? minPlayers,
+    int? maxPlayers,
+    int? minMinutes,
+    int? maxMinutes,
+    int? minAge,
+
+    /// Storage path from `catalog_games`, not a URL. Not turned into an image
+    /// URL in #3 (the cover stays a placeholder).
+    String? imagePath,
+    @Default(<String>[]) List<String> publisherNames,
+
+    /// Alternative title that matched better than the main title.
+    String? matchedAltTitle,
+  }) = _CatalogGameSummary;
+}

app/lib/features/catalog/domain/catalog_game_summary.freezed.dart

@@ -0,0 +1,321 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_game_summary.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogGameSummary {
+
+ String get id; String get title; int? get year; int? get minPlayers; int? get maxPlayers; int? get minMinutes; int? get maxMinutes; int? get minAge;/// Storage path from `catalog_games`, not a URL. Not turned into an image
+/// URL in #3 (the cover stays a placeholder).
+ String? get imagePath; List<String> get publisherNames;/// Alternative title that matched better than the main title.
+ String? get matchedAltTitle;
+/// Create a copy of CatalogGameSummary
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogGameSummaryCopyWith<CatalogGameSummary> get copyWith => _$CatalogGameSummaryCopyWithImpl<CatalogGameSummary>(this as CatalogGameSummary, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogGameSummary;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogGameSummary&&(identical(other.id, _this.id) || other.id == _this.id)&&(identical(other.title, _this.title) || other.title == _this.title)&&(identical(other.year, _this.year) || other.year == _this.year)&&(identical(other.minPlayers, _this.minPlayers) || other.minPlayers == _this.minPlayers)&&(identical(other.maxPlayers, _this.maxPlayers) || other.maxPlayers == _this.maxPlayers)&&(identical(other.minMinutes, _this.minMinutes) || other.minMinutes == _this.minMinutes)&&(identical(other.maxMinutes, _this.maxMinutes) || other.maxMinutes == _this.maxMinutes)&&(identical(other.minAge, _this.minAge) || other.minAge == _this.minAge)&&(identical(other.imagePath, _this.imagePath) || other.imagePath == _this.imagePath)&&const DeepCollectionEquality().equals(other.publisherNames, _this.publisherNames)&&(identical(other.matchedAltTitle, _this.matchedAltTitle) || other.matchedAltTitle == _this.matchedAltTitle));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogGameSummary;
+  return Object.hash(runtimeType,_this.id,_this.title,_this.year,_this.minPlayers,_this.maxPlayers,_this.minMinutes,_this.maxMinutes,_this.minAge,_this.imagePath,const DeepCollectionEquality().hash(_this.publisherNames),_this.matchedAltTitle);
+}
+
+@override
+String toString() {
+  final _this = this as CatalogGameSummary;
+  return 'CatalogGameSummary(id: ${_this.id}, title: ${_this.title}, year: ${_this.year}, minPlayers: ${_this.minPlayers}, maxPlayers: ${_this.maxPlayers}, minMinutes: ${_this.minMinutes}, maxMinutes: ${_this.maxMinutes}, minAge: ${_this.minAge}, imagePath: ${_this.imagePath}, publisherNames: ${_this.publisherNames}, matchedAltTitle: ${_this.matchedAltTitle})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogGameSummaryCopyWith<$Res>  {
+  factory $CatalogGameSummaryCopyWith(CatalogGameSummary value, $Res Function(CatalogGameSummary) _then) = _$CatalogGameSummaryCopyWithImpl;
+@useResult
+$Res call({
+ String id, String title, int? year, int? minPlayers, int? maxPlayers, int? minMinutes, int? maxMinutes, int? minAge, String? imagePath, List<String> publisherNames, String? matchedAltTitle
+});
+
+
+
+
+}
+/// @nodoc
+class _$CatalogGameSummaryCopyWithImpl<$Res>
+    implements $CatalogGameSummaryCopyWith<$Res> {
+  _$CatalogGameSummaryCopyWithImpl(this._self, this._then);
+
+  final CatalogGameSummary _self;
+  final $Res Function(CatalogGameSummary) _then;
+
+/// Create a copy of CatalogGameSummary
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? id = null,Object? title = null,Object? year = freezed,Object? minPlayers = freezed,Object? maxPlayers = freezed,Object? minMinutes = freezed,Object? maxMinutes = freezed,Object? minAge = freezed,Object? imagePath = freezed,Object? publisherNames = null,Object? matchedAltTitle = freezed,}) {
+  return _then(CatalogGameSummary(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,title: null == title ? _self.title : title // ignore: cast_nullable_to_non_nullable
+as String,year: freezed == year ? _self.year : year // ignore: cast_nullable_to_non_nullable
+as int?,minPlayers: freezed == minPlayers ? _self.minPlayers : minPlayers // ignore: cast_nullable_to_non_nullable
+as int?,maxPlayers: freezed == maxPlayers ? _self.maxPlayers : maxPlayers // ignore: cast_nullable_to_non_nullable
+as int?,minMinutes: freezed == minMinutes ? _self.minMinutes : minMinutes // ignore: cast_nullable_to_non_nullable
+as int?,maxMinutes: freezed == maxMinutes ? _self.maxMinutes : maxMinutes // ignore: cast_nullable_to_non_nullable
+as int?,minAge: freezed == minAge ? _self.minAge : minAge // ignore: cast_nullable_to_non_nullable
+as int?,imagePath: freezed == imagePath ? _self.imagePath : imagePath // ignore: cast_nullable_to_non_nullable
+as String?,publisherNames: null == publisherNames ? _self.publisherNames : publisherNames // ignore: cast_nullable_to_non_nullable
+as List<String>,matchedAltTitle: freezed == matchedAltTitle ? _self.matchedAltTitle : matchedAltTitle // ignore: cast_nullable_to_non_nullable
+as String?,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogGameSummary].
+extension CatalogGameSummaryPatterns on CatalogGameSummary {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogGameSummary value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogGameSummary() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogGameSummary value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogGameSummary():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogGameSummary value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogGameSummary() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( String id,  String title,  int? year,  int? minPlayers,  int? maxPlayers,  int? minMinutes,  int? maxMinutes,  int? minAge,  String? imagePath,  List<String> publisherNames,  String? matchedAltTitle)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogGameSummary() when $default != null:
+return $default(_that.id,_that.title,_that.year,_that.minPlayers,_that.maxPlayers,_that.minMinutes,_that.maxMinutes,_that.minAge,_that.imagePath,_that.publisherNames,_that.matchedAltTitle);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( String id,  String title,  int? year,  int? minPlayers,  int? maxPlayers,  int? minMinutes,  int? maxMinutes,  int? minAge,  String? imagePath,  List<String> publisherNames,  String? matchedAltTitle)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogGameSummary():
+return $default(_that.id,_that.title,_that.year,_that.minPlayers,_that.maxPlayers,_that.minMinutes,_that.maxMinutes,_that.minAge,_that.imagePath,_that.publisherNames,_that.matchedAltTitle);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( String id,  String title,  int? year,  int? minPlayers,  int? maxPlayers,  int? minMinutes,  int? maxMinutes,  int? minAge,  String? imagePath,  List<String> publisherNames,  String? matchedAltTitle)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogGameSummary() when $default != null:
+return $default(_that.id,_that.title,_that.year,_that.minPlayers,_that.maxPlayers,_that.minMinutes,_that.maxMinutes,_that.minAge,_that.imagePath,_that.publisherNames,_that.matchedAltTitle);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogGameSummary implements CatalogGameSummary {
+  const _CatalogGameSummary({required this.id, required this.title, this.year, this.minPlayers, this.maxPlayers, this.minMinutes, this.maxMinutes, this.minAge, this.imagePath,  List<String> publisherNames = const <String>[], this.matchedAltTitle}): _publisherNames = publisherNames;
+  
+
+@override final  String id;
+@override final  String title;
+@override final  int? year;
+@override final  int? minPlayers;
+@override final  int? maxPlayers;
+@override final  int? minMinutes;
+@override final  int? maxMinutes;
+@override final  int? minAge;
+/// Storage path from `catalog_games`, not a URL. Not turned into an image
+/// URL in #3 (the cover stays a placeholder).
+@override final  String? imagePath;
+ final  List<String> _publisherNames;
+@override@JsonKey() List<String> get publisherNames {
+  if (_publisherNames is EqualUnmodifiableListView) return _publisherNames;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableListView(_publisherNames);
+}
+
+/// Alternative title that matched better than the main title.
+@override final  String? matchedAltTitle;
+
+/// Create a copy of CatalogGameSummary
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogGameSummaryCopyWith<_CatalogGameSummary> get copyWith => __$CatalogGameSummaryCopyWithImpl<_CatalogGameSummary>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogGameSummary&&(identical(other.id, id) || other.id == id)&&(identical(other.title, title) || other.title == title)&&(identical(other.year, year) || other.year == year)&&(identical(other.minPlayers, minPlayers) || other.minPlayers == minPlayers)&&(identical(other.maxPlayers, maxPlayers) || other.maxPlayers == maxPlayers)&&(identical(other.minMinutes, minMinutes) || other.minMinutes == minMinutes)&&(identical(other.maxMinutes, maxMinutes) || other.maxMinutes == maxMinutes)&&(identical(other.minAge, minAge) || other.minAge == minAge)&&(identical(other.imagePath, imagePath) || other.imagePath == imagePath)&&const DeepCollectionEquality().equals(other.publisherNames, _publisherNames)&&(identical(other.matchedAltTitle, matchedAltTitle) || other.matchedAltTitle == matchedAltTitle));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,id,title,year,minPlayers,maxPlayers,minMinutes,maxMinutes,minAge,imagePath,const DeepCollectionEquality().hash(_publisherNames),matchedAltTitle);
+}
+
+@override
+String toString() {
+    return 'CatalogGameSummary(id: $id, title: $title, year: $year, minPlayers: $minPlayers, maxPlayers: $maxPlayers, minMinutes: $minMinutes, maxMinutes: $maxMinutes, minAge: $minAge, imagePath: $imagePath, publisherNames: $publisherNames, matchedAltTitle: $matchedAltTitle)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogGameSummaryCopyWith<$Res> implements $CatalogGameSummaryCopyWith<$Res> {
+  factory _$CatalogGameSummaryCopyWith(_CatalogGameSummary value, $Res Function(_CatalogGameSummary) _then) = __$CatalogGameSummaryCopyWithImpl;
+@override @useResult
+$Res call({
+ String id, String title, int? year, int? minPlayers, int? maxPlayers, int? minMinutes, int? maxMinutes, int? minAge, String? imagePath, List<String> publisherNames, String? matchedAltTitle
+});
+
+
+
+
+}
+/// @nodoc
+class __$CatalogGameSummaryCopyWithImpl<$Res>
+    implements _$CatalogGameSummaryCopyWith<$Res> {
+  __$CatalogGameSummaryCopyWithImpl(this._self, this._then);
+
+  final _CatalogGameSummary _self;
+  final $Res Function(_CatalogGameSummary) _then;
+
+/// Create a copy of CatalogGameSummary
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? id = null,Object? title = null,Object? year = freezed,Object? minPlayers = freezed,Object? maxPlayers = freezed,Object? minMinutes = freezed,Object? maxMinutes = freezed,Object? minAge = freezed,Object? imagePath = freezed,Object? publisherNames = null,Object? matchedAltTitle = freezed,}) {
+  return _then(_CatalogGameSummary(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,title: null == title ? _self.title : title // ignore: cast_nullable_to_non_nullable
+as String,year: freezed == year ? _self.year : year // ignore: cast_nullable_to_non_nullable
+as int?,minPlayers: freezed == minPlayers ? _self.minPlayers : minPlayers // ignore: cast_nullable_to_non_nullable
+as int?,maxPlayers: freezed == maxPlayers ? _self.maxPlayers : maxPlayers // ignore: cast_nullable_to_non_nullable
+as int?,minMinutes: freezed == minMinutes ? _self.minMinutes : minMinutes // ignore: cast_nullable_to_non_nullable
+as int?,maxMinutes: freezed == maxMinutes ? _self.maxMinutes : maxMinutes // ignore: cast_nullable_to_non_nullable
+as int?,minAge: freezed == minAge ? _self.minAge : minAge // ignore: cast_nullable_to_non_nullable
+as int?,imagePath: freezed == imagePath ? _self.imagePath : imagePath // ignore: cast_nullable_to_non_nullable
+as String?,publisherNames: null == publisherNames ? _self._publisherNames : publisherNames // ignore: cast_nullable_to_non_nullable
+as List<String>,matchedAltTitle: freezed == matchedAltTitle ? _self.matchedAltTitle : matchedAltTitle // ignore: cast_nullable_to_non_nullable
+as String?,
+  ));
+}
+
+
+}
+
+// dart format on

app/lib/features/catalog/domain/catalog_repository.dart

@@ -0,0 +1,19 @@
+import 'package:shuffle/core/result/result.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_page.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+
+/// Read access to the catalog (Spec #3 § 5.2).
+abstract interface class CatalogRepository {
+  /// One page of hits for [query], starting at [offset].
+  Future<Result<CatalogSearchPage, CatalogFailure>> search(
+    CatalogSearchQuery query, {
+    required int offset,
+    int limit = CatalogSearchLimits.pageSize,
+  });
+
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchGenres();
+
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchMechanics();
+}

app/lib/features/catalog/domain/catalog_search_page.dart

@@ -0,0 +1,13 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:shuffle/features/catalog/domain/catalog_game_summary.dart';
+
+part 'catalog_search_page.freezed.dart';
+
+/// One page of search results plus the total number of hits.
+@freezed
+abstract class CatalogSearchPage with _$CatalogSearchPage {
+  const factory CatalogSearchPage({
+    required List<CatalogGameSummary> items,
+    required int totalCount,
+  }) = _CatalogSearchPage;
+}

app/lib/features/catalog/domain/catalog_search_page.freezed.dart

@@ -0,0 +1,288 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_search_page.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogSearchPage {
+
+ List<CatalogGameSummary> get items; int get totalCount;
+/// Create a copy of CatalogSearchPage
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogSearchPageCopyWith<CatalogSearchPage> get copyWith => _$CatalogSearchPageCopyWithImpl<CatalogSearchPage>(this as CatalogSearchPage, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogSearchPage;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogSearchPage&&const DeepCollectionEquality().equals(other.items, _this.items)&&(identical(other.totalCount, _this.totalCount) || other.totalCount == _this.totalCount));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogSearchPage;
+  return Object.hash(runtimeType,const DeepCollectionEquality().hash(_this.items),_this.totalCount);
+}
+
+@override
+String toString() {
+  final _this = this as CatalogSearchPage;
+  return 'CatalogSearchPage(items: ${_this.items}, totalCount: ${_this.totalCount})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogSearchPageCopyWith<$Res>  {
+  factory $CatalogSearchPageCopyWith(CatalogSearchPage value, $Res Function(CatalogSearchPage) _then) = _$CatalogSearchPageCopyWithImpl;
+@useResult
+$Res call({
+ List<CatalogGameSummary> items, int totalCount
+});
+
+
+
+
+}
+/// @nodoc
+class _$CatalogSearchPageCopyWithImpl<$Res>
+    implements $CatalogSearchPageCopyWith<$Res> {
+  _$CatalogSearchPageCopyWithImpl(this._self, this._then);
+
+  final CatalogSearchPage _self;
+  final $Res Function(CatalogSearchPage) _then;
+
+/// Create a copy of CatalogSearchPage
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? items = null,Object? totalCount = null,}) {
+  return _then(CatalogSearchPage(
+items: null == items ? _self.items : items // ignore: cast_nullable_to_non_nullable
+as List<CatalogGameSummary>,totalCount: null == totalCount ? _self.totalCount : totalCount // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogSearchPage].
+extension CatalogSearchPagePatterns on CatalogSearchPage {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogSearchPage value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogSearchPage() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogSearchPage value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchPage():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogSearchPage value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchPage() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( List<CatalogGameSummary> items,  int totalCount)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogSearchPage() when $default != null:
+return $default(_that.items,_that.totalCount);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( List<CatalogGameSummary> items,  int totalCount)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchPage():
+return $default(_that.items,_that.totalCount);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( List<CatalogGameSummary> items,  int totalCount)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchPage() when $default != null:
+return $default(_that.items,_that.totalCount);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogSearchPage implements CatalogSearchPage {
+  const _CatalogSearchPage({required  List<CatalogGameSummary> items, required this.totalCount}): _items = items;
+  
+
+ final  List<CatalogGameSummary> _items;
+@override List<CatalogGameSummary> get items {
+  if (_items is EqualUnmodifiableListView) return _items;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableListView(_items);
+}
+
+@override final  int totalCount;
+
+/// Create a copy of CatalogSearchPage
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogSearchPageCopyWith<_CatalogSearchPage> get copyWith => __$CatalogSearchPageCopyWithImpl<_CatalogSearchPage>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogSearchPage&&const DeepCollectionEquality().equals(other.items, _items)&&(identical(other.totalCount, totalCount) || other.totalCount == totalCount));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,const DeepCollectionEquality().hash(_items),totalCount);
+}
+
+@override
+String toString() {
+    return 'CatalogSearchPage(items: $items, totalCount: $totalCount)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogSearchPageCopyWith<$Res> implements $CatalogSearchPageCopyWith<$Res> {
+  factory _$CatalogSearchPageCopyWith(_CatalogSearchPage value, $Res Function(_CatalogSearchPage) _then) = __$CatalogSearchPageCopyWithImpl;
+@override @useResult
+$Res call({
+ List<CatalogGameSummary> items, int totalCount
+});
+
+
+
+
+}
+/// @nodoc
+class __$CatalogSearchPageCopyWithImpl<$Res>
+    implements _$CatalogSearchPageCopyWith<$Res> {
+  __$CatalogSearchPageCopyWithImpl(this._self, this._then);
+
+  final _CatalogSearchPage _self;
+  final $Res Function(_CatalogSearchPage) _then;
+
+/// Create a copy of CatalogSearchPage
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? items = null,Object? totalCount = null,}) {
+  return _then(_CatalogSearchPage(
+items: null == items ? _self._items : items // ignore: cast_nullable_to_non_nullable
+as List<CatalogGameSummary>,totalCount: null == totalCount ? _self.totalCount : totalCount // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+
+
+}
+
+// dart format on

app/lib/features/catalog/domain/catalog_search_query.dart

@@ -0,0 +1,117 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'catalog_search_query.freezed.dart';
+
+/// Allowed values and limits of the search (Spec #3 § 4.2, § 5.2).
+abstract final class CatalogSearchLimits {
+  /// Longest search text (the backend rejects more).
+  static const int maxTextLength = 100;
+
+  /// Searches start at this many characters; less acts like "no search text".
+  static const int minTextLength = 2;
+
+  static const int minPlayers = 1;
+  static const int maxPlayers = 12;
+
+  /// "Up to X minutes" steps.
+  static const List<int> maxMinutesSteps = [30, 45, 60, 90, 120, 180];
+
+  /// "Suitable from X years" steps.
+  static const List<int> ageSteps = [6, 8, 10, 12, 14, 16, 18];
+
+  /// The backend rejects search texts with more words.
+  static const int maxWords = 10;
+
+  /// Most genres or mechanics that can be selected at once.
+  static const int maxTerms = 20;
+
+  static const int pageSize = 30;
+
+  /// The backend does not page beyond this offset.
+  static const int maxOffset = 10000;
+}
+
+/// Filters of a search. All set filters apply together (AND, Spec #3 E7).
+@freezed
+abstract class CatalogFilters with _$CatalogFilters {
+  @Assert(
+    'players == null || (players >= 1 && players <= 12)',
+    'players out of range',
+  )
+  @Assert('maxMinutes == null || maxMinutes > 0', 'maxMinutes must be positive')
+  @Assert('minAgeSuitable == null || minAgeSuitable >= 0', 'age out of range')
+  const factory CatalogFilters({
+    /// Number of players the game must support.
+    int? players,
+
+    /// Game lasts at most this many minutes.
+    int? maxMinutes,
+
+    /// Game is suitable for players of this age (minimum age at most this).
+    int? minAgeSuitable,
+
+    /// At most [CatalogSearchLimits.maxTerms]; the UI and the URL parser
+    /// enforce it.
+    @Default(<String>{}) Set<String> genreIds,
+    @Default(<String>{}) Set<String> mechanicIds,
+  }) = _CatalogFilters;
+
+  const CatalogFilters._();
+
+  int get activeCount =>
+      (players != null ? 1 : 0) +
+      (maxMinutes != null ? 1 : 0) +
+      (minAgeSuitable != null ? 1 : 0) +
+      genreIds.length +
+      mechanicIds.length;
+
+  bool get isEmpty => activeCount == 0;
+}
+
+/// A search: text plus filters.
+@freezed
+abstract class CatalogSearchQuery with _$CatalogSearchQuery {
+  @Assert('text.length <= 100', 'text longer than the maximum length')
+  const factory CatalogSearchQuery({
+    /// Trimmed search text, at most 100 characters.
+    @Default('') String text,
+    @Default(CatalogFilters()) CatalogFilters filters,
+  }) = _CatalogSearchQuery;
+
+  const CatalogSearchQuery._();
+
+  static final RegExp _word = RegExp(r'[\p{L}\p{N}]+', unicode: true);
+
+  /// Trims [raw] and cuts it to the maximum length and to at most
+  /// [CatalogSearchLimits.maxWords] words. The backend counts words after its
+  /// normalization (punctuation separates words, one-letter words count) and
+  /// rejects more; this is the client-side approximation, the rest is cut off
+  /// silently.
+  static String cleanText(String raw) {
+    var text = raw.trim();
+    if (text.length > CatalogSearchLimits.maxTextLength) {
+      text = text.substring(0, CatalogSearchLimits.maxTextLength).trim();
+    }
+    var count = 0;
+    for (final match in _word.allMatches(text)) {
+      if (++count == CatalogSearchLimits.maxWords) {
+        return text.substring(0, match.end);
+      }
+    }
+    return text;
+  }
+
+  /// Whether the text is long enough to count as a search term.
+  bool get hasText => text.length >= CatalogSearchLimits.minTextLength;
+
+  bool get hasFilters => !filters.isEmpty;
+
+  int get activeFilterCount => filters.activeCount;
+
+  /// No search term and no filters: the whole catalog (Spec #3 E8).
+  bool get isEmpty => !hasText && !hasFilters;
+
+  /// The query as the backend sees it: a text below the minimum length is
+  /// dropped.
+  CatalogSearchQuery get effective => hasText ? this : copyWith(text: '');
+}

app/lib/features/catalog/domain/catalog_search_query.freezed.dart

@@ -0,0 +1,602 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_search_query.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogFilters {
+
+/// Number of players the game must support.
+ int? get players;/// Game lasts at most this many minutes.
+ int? get maxMinutes;/// Game is suitable for players of this age (minimum age at most this).
+ int? get minAgeSuitable;/// At most [CatalogSearchLimits.maxTerms]; the UI and the URL parser
+/// enforce it.
+ Set<String> get genreIds; Set<String> get mechanicIds;
+/// Create a copy of CatalogFilters
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogFiltersCopyWith<CatalogFilters> get copyWith => _$CatalogFiltersCopyWithImpl<CatalogFilters>(this as CatalogFilters, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogFilters;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogFilters&&(identical(other.players, _this.players) || other.players == _this.players)&&(identical(other.maxMinutes, _this.maxMinutes) || other.maxMinutes == _this.maxMinutes)&&(identical(other.minAgeSuitable, _this.minAgeSuitable) || other.minAgeSuitable == _this.minAgeSuitable)&&const DeepCollectionEquality().equals(other.genreIds, _this.genreIds)&&const DeepCollectionEquality().equals(other.mechanicIds, _this.mechanicIds));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogFilters;
+  return Object.hash(runtimeType,_this.players,_this.maxMinutes,_this.minAgeSuitable,const DeepCollectionEquality().hash(_this.genreIds),const DeepCollectionEquality().hash(_this.mechanicIds));
+}
+
+@override
+String toString() {
+  final _this = this as CatalogFilters;
+  return 'CatalogFilters(players: ${_this.players}, maxMinutes: ${_this.maxMinutes}, minAgeSuitable: ${_this.minAgeSuitable}, genreIds: ${_this.genreIds}, mechanicIds: ${_this.mechanicIds})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogFiltersCopyWith<$Res>  {
+  factory $CatalogFiltersCopyWith(CatalogFilters value, $Res Function(CatalogFilters) _then) = _$CatalogFiltersCopyWithImpl;
+@useResult
+$Res call({
+ int? players, int? maxMinutes, int? minAgeSuitable, Set<String> genreIds, Set<String> mechanicIds
+});
+
+
+
+
+}
+/// @nodoc
+class _$CatalogFiltersCopyWithImpl<$Res>
+    implements $CatalogFiltersCopyWith<$Res> {
+  _$CatalogFiltersCopyWithImpl(this._self, this._then);
+
+  final CatalogFilters _self;
+  final $Res Function(CatalogFilters) _then;
+
+/// Create a copy of CatalogFilters
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? players = freezed,Object? maxMinutes = freezed,Object? minAgeSuitable = freezed,Object? genreIds = null,Object? mechanicIds = null,}) {
+  return _then(CatalogFilters(
+players: freezed == players ? _self.players : players // ignore: cast_nullable_to_non_nullable
+as int?,maxMinutes: freezed == maxMinutes ? _self.maxMinutes : maxMinutes // ignore: cast_nullable_to_non_nullable
+as int?,minAgeSuitable: freezed == minAgeSuitable ? _self.minAgeSuitable : minAgeSuitable // ignore: cast_nullable_to_non_nullable
+as int?,genreIds: null == genreIds ? _self.genreIds : genreIds // ignore: cast_nullable_to_non_nullable
+as Set<String>,mechanicIds: null == mechanicIds ? _self.mechanicIds : mechanicIds // ignore: cast_nullable_to_non_nullable
+as Set<String>,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogFilters].
+extension CatalogFiltersPatterns on CatalogFilters {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogFilters value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogFilters() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogFilters value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogFilters():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogFilters value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogFilters() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( int? players,  int? maxMinutes,  int? minAgeSuitable,  Set<String> genreIds,  Set<String> mechanicIds)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogFilters() when $default != null:
+return $default(_that.players,_that.maxMinutes,_that.minAgeSuitable,_that.genreIds,_that.mechanicIds);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( int? players,  int? maxMinutes,  int? minAgeSuitable,  Set<String> genreIds,  Set<String> mechanicIds)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogFilters():
+return $default(_that.players,_that.maxMinutes,_that.minAgeSuitable,_that.genreIds,_that.mechanicIds);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( int? players,  int? maxMinutes,  int? minAgeSuitable,  Set<String> genreIds,  Set<String> mechanicIds)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogFilters() when $default != null:
+return $default(_that.players,_that.maxMinutes,_that.minAgeSuitable,_that.genreIds,_that.mechanicIds);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogFilters extends CatalogFilters {
+  const _CatalogFilters({this.players, this.maxMinutes, this.minAgeSuitable,  Set<String> genreIds = const <String>{},  Set<String> mechanicIds = const <String>{}}): assert(players == null || (players >= 1 && players <= 12), 'players out of range'),assert(maxMinutes == null || maxMinutes > 0, 'maxMinutes must be positive'),assert(minAgeSuitable == null || minAgeSuitable >= 0, 'age out of range'),_genreIds = genreIds,_mechanicIds = mechanicIds,super._();
+  
+
+/// Number of players the game must support.
+@override final  int? players;
+/// Game lasts at most this many minutes.
+@override final  int? maxMinutes;
+/// Game is suitable for players of this age (minimum age at most this).
+@override final  int? minAgeSuitable;
+/// At most [CatalogSearchLimits.maxTerms]; the UI and the URL parser
+/// enforce it.
+ final  Set<String> _genreIds;
+/// At most [CatalogSearchLimits.maxTerms]; the UI and the URL parser
+/// enforce it.
+@override@JsonKey() Set<String> get genreIds {
+  if (_genreIds is EqualUnmodifiableSetView) return _genreIds;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableSetView(_genreIds);
+}
+
+ final  Set<String> _mechanicIds;
+@override@JsonKey() Set<String> get mechanicIds {
+  if (_mechanicIds is EqualUnmodifiableSetView) return _mechanicIds;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableSetView(_mechanicIds);
+}
+
+
+/// Create a copy of CatalogFilters
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogFiltersCopyWith<_CatalogFilters> get copyWith => __$CatalogFiltersCopyWithImpl<_CatalogFilters>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogFilters&&(identical(other.players, players) || other.players == players)&&(identical(other.maxMinutes, maxMinutes) || other.maxMinutes == maxMinutes)&&(identical(other.minAgeSuitable, minAgeSuitable) || other.minAgeSuitable == minAgeSuitable)&&const DeepCollectionEquality().equals(other.genreIds, _genreIds)&&const DeepCollectionEquality().equals(other.mechanicIds, _mechanicIds));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,players,maxMinutes,minAgeSuitable,const DeepCollectionEquality().hash(_genreIds),const DeepCollectionEquality().hash(_mechanicIds));
+}
+
+@override
+String toString() {
+    return 'CatalogFilters(players: $players, maxMinutes: $maxMinutes, minAgeSuitable: $minAgeSuitable, genreIds: $genreIds, mechanicIds: $mechanicIds)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogFiltersCopyWith<$Res> implements $CatalogFiltersCopyWith<$Res> {
+  factory _$CatalogFiltersCopyWith(_CatalogFilters value, $Res Function(_CatalogFilters) _then) = __$CatalogFiltersCopyWithImpl;
+@override @useResult
+$Res call({
+ int? players, int? maxMinutes, int? minAgeSuitable, Set<String> genreIds, Set<String> mechanicIds
+});
+
+
+
+
+}
+/// @nodoc
+class __$CatalogFiltersCopyWithImpl<$Res>
+    implements _$CatalogFiltersCopyWith<$Res> {
+  __$CatalogFiltersCopyWithImpl(this._self, this._then);
+
+  final _CatalogFilters _self;
+  final $Res Function(_CatalogFilters) _then;
+
+/// Create a copy of CatalogFilters
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? players = freezed,Object? maxMinutes = freezed,Object? minAgeSuitable = freezed,Object? genreIds = null,Object? mechanicIds = null,}) {
+  return _then(_CatalogFilters(
+players: freezed == players ? _self.players : players // ignore: cast_nullable_to_non_nullable
+as int?,maxMinutes: freezed == maxMinutes ? _self.maxMinutes : maxMinutes // ignore: cast_nullable_to_non_nullable
+as int?,minAgeSuitable: freezed == minAgeSuitable ? _self.minAgeSuitable : minAgeSuitable // ignore: cast_nullable_to_non_nullable
+as int?,genreIds: null == genreIds ? _self._genreIds : genreIds // ignore: cast_nullable_to_non_nullable
+as Set<String>,mechanicIds: null == mechanicIds ? _self._mechanicIds : mechanicIds // ignore: cast_nullable_to_non_nullable
+as Set<String>,
+  ));
+}
+
+
+}
+
+/// @nodoc
+mixin _$CatalogSearchQuery {
+
+/// Trimmed search text, at most 100 characters.
+ String get text; CatalogFilters get filters;
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogSearchQueryCopyWith<CatalogSearchQuery> get copyWith => _$CatalogSearchQueryCopyWithImpl<CatalogSearchQuery>(this as CatalogSearchQuery, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogSearchQuery;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogSearchQuery&&(identical(other.text, _this.text) || other.text == _this.text)&&(identical(other.filters, _this.filters) || other.filters == _this.filters));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogSearchQuery;
+  return Object.hash(runtimeType,_this.text,_this.filters);
+}
+
+@override
+String toString() {
+  final _this = this as CatalogSearchQuery;
+  return 'CatalogSearchQuery(text: ${_this.text}, filters: ${_this.filters})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogSearchQueryCopyWith<$Res>  {
+  factory $CatalogSearchQueryCopyWith(CatalogSearchQuery value, $Res Function(CatalogSearchQuery) _then) = _$CatalogSearchQueryCopyWithImpl;
+@useResult
+$Res call({
+ String text, CatalogFilters filters
+});
+
+
+$CatalogFiltersCopyWith<$Res> get filters;
+
+}
+/// @nodoc
+class _$CatalogSearchQueryCopyWithImpl<$Res>
+    implements $CatalogSearchQueryCopyWith<$Res> {
+  _$CatalogSearchQueryCopyWithImpl(this._self, this._then);
+
+  final CatalogSearchQuery _self;
+  final $Res Function(CatalogSearchQuery) _then;
+
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? text = null,Object? filters = null,}) {
+  return _then(CatalogSearchQuery(
+text: null == text ? _self.text : text // ignore: cast_nullable_to_non_nullable
+as String,filters: null == filters ? _self.filters : filters // ignore: cast_nullable_to_non_nullable
+as CatalogFilters,
+  ));
+}
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFiltersCopyWith<$Res> get filters {
+  
+  return $CatalogFiltersCopyWith<$Res>(_self.filters, (value) {
+    return _then(_self.copyWith(filters: value));
+  });
+}
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogSearchQuery].
+extension CatalogSearchQueryPatterns on CatalogSearchQuery {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogSearchQuery value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogSearchQuery() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogSearchQuery value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchQuery():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogSearchQuery value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchQuery() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( String text,  CatalogFilters filters)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogSearchQuery() when $default != null:
+return $default(_that.text,_that.filters);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( String text,  CatalogFilters filters)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchQuery():
+return $default(_that.text,_that.filters);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( String text,  CatalogFilters filters)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchQuery() when $default != null:
+return $default(_that.text,_that.filters);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogSearchQuery extends CatalogSearchQuery {
+  const _CatalogSearchQuery({this.text = '', this.filters = const CatalogFilters()}): assert(text.length <= 100, 'text longer than the maximum length'),super._();
+  
+
+/// Trimmed search text, at most 100 characters.
+@override@JsonKey() final  String text;
+@override@JsonKey() final  CatalogFilters filters;
+
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogSearchQueryCopyWith<_CatalogSearchQuery> get copyWith => __$CatalogSearchQueryCopyWithImpl<_CatalogSearchQuery>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogSearchQuery&&(identical(other.text, text) || other.text == text)&&(identical(other.filters, filters) || other.filters == filters));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,text,filters);
+}
+
+@override
+String toString() {
+    return 'CatalogSearchQuery(text: $text, filters: $filters)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogSearchQueryCopyWith<$Res> implements $CatalogSearchQueryCopyWith<$Res> {
+  factory _$CatalogSearchQueryCopyWith(_CatalogSearchQuery value, $Res Function(_CatalogSearchQuery) _then) = __$CatalogSearchQueryCopyWithImpl;
+@override @useResult
+$Res call({
+ String text, CatalogFilters filters
+});
+
+
+@override $CatalogFiltersCopyWith<$Res> get filters;
+
+}
+/// @nodoc
+class __$CatalogSearchQueryCopyWithImpl<$Res>
+    implements _$CatalogSearchQueryCopyWith<$Res> {
+  __$CatalogSearchQueryCopyWithImpl(this._self, this._then);
+
+  final _CatalogSearchQuery _self;
+  final $Res Function(_CatalogSearchQuery) _then;
+
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? text = null,Object? filters = null,}) {
+  return _then(_CatalogSearchQuery(
+text: null == text ? _self.text : text // ignore: cast_nullable_to_non_nullable
+as String,filters: null == filters ? _self.filters : filters // ignore: cast_nullable_to_non_nullable
+as CatalogFilters,
+  ));
+}
+
+/// Create a copy of CatalogSearchQuery
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFiltersCopyWith<$Res> get filters {
+  
+  return $CatalogFiltersCopyWith<$Res>(_self.filters, (value) {
+    return _then(_self.copyWith(filters: value));
+  });
+}
+}
+
+// dart format on

app/lib/features/catalog/domain/catalog_term.dart

@@ -0,0 +1,20 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'catalog_term.freezed.dart';
+
+/// A controlled vocabulary entry (genre or mechanic) with both languages.
+@freezed
+abstract class CatalogTerm with _$CatalogTerm {
+  const factory CatalogTerm({
+    required String id,
+    required String nameDe,
+    required String nameEn,
+  }) = _CatalogTerm;
+
+  const CatalogTerm._();
+
+  /// German name for `de`, English for every other language (QUE-05 criterion
+  /// 4: English is the fallback).
+  String localizedName(String languageCode) =>
+      languageCode == 'de' ? nameDe : nameEn;
+}

app/lib/features/catalog/domain/catalog_term.freezed.dart

@@ -0,0 +1,285 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_term.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogTerm {
+
+ String get id; String get nameDe; String get nameEn;
+/// Create a copy of CatalogTerm
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogTermCopyWith<CatalogTerm> get copyWith => _$CatalogTermCopyWithImpl<CatalogTerm>(this as CatalogTerm, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogTerm;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogTerm&&(identical(other.id, _this.id) || other.id == _this.id)&&(identical(other.nameDe, _this.nameDe) || other.nameDe == _this.nameDe)&&(identical(other.nameEn, _this.nameEn) || other.nameEn == _this.nameEn));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogTerm;
+  return Object.hash(runtimeType,_this.id,_this.nameDe,_this.nameEn);
+}
+
+@override
+String toString() {
+  final _this = this as CatalogTerm;
+  return 'CatalogTerm(id: ${_this.id}, nameDe: ${_this.nameDe}, nameEn: ${_this.nameEn})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogTermCopyWith<$Res>  {
+  factory $CatalogTermCopyWith(CatalogTerm value, $Res Function(CatalogTerm) _then) = _$CatalogTermCopyWithImpl;
+@useResult
+$Res call({
+ String id, String nameDe, String nameEn
+});
+
+
+
+
+}
+/// @nodoc
+class _$CatalogTermCopyWithImpl<$Res>
+    implements $CatalogTermCopyWith<$Res> {
+  _$CatalogTermCopyWithImpl(this._self, this._then);
+
+  final CatalogTerm _self;
+  final $Res Function(CatalogTerm) _then;
+
+/// Create a copy of CatalogTerm
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? id = null,Object? nameDe = null,Object? nameEn = null,}) {
+  return _then(CatalogTerm(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,nameDe: null == nameDe ? _self.nameDe : nameDe // ignore: cast_nullable_to_non_nullable
+as String,nameEn: null == nameEn ? _self.nameEn : nameEn // ignore: cast_nullable_to_non_nullable
+as String,
+  ));
+}
+
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogTerm].
+extension CatalogTermPatterns on CatalogTerm {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogTerm value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogTerm() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogTerm value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogTerm():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogTerm value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogTerm() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( String id,  String nameDe,  String nameEn)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogTerm() when $default != null:
+return $default(_that.id,_that.nameDe,_that.nameEn);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( String id,  String nameDe,  String nameEn)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogTerm():
+return $default(_that.id,_that.nameDe,_that.nameEn);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( String id,  String nameDe,  String nameEn)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogTerm() when $default != null:
+return $default(_that.id,_that.nameDe,_that.nameEn);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogTerm extends CatalogTerm {
+  const _CatalogTerm({required this.id, required this.nameDe, required this.nameEn}): super._();
+  
+
+@override final  String id;
+@override final  String nameDe;
+@override final  String nameEn;
+
+/// Create a copy of CatalogTerm
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogTermCopyWith<_CatalogTerm> get copyWith => __$CatalogTermCopyWithImpl<_CatalogTerm>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogTerm&&(identical(other.id, id) || other.id == id)&&(identical(other.nameDe, nameDe) || other.nameDe == nameDe)&&(identical(other.nameEn, nameEn) || other.nameEn == nameEn));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,id,nameDe,nameEn);
+}
+
+@override
+String toString() {
+    return 'CatalogTerm(id: $id, nameDe: $nameDe, nameEn: $nameEn)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogTermCopyWith<$Res> implements $CatalogTermCopyWith<$Res> {
+  factory _$CatalogTermCopyWith(_CatalogTerm value, $Res Function(_CatalogTerm) _then) = __$CatalogTermCopyWithImpl;
+@override @useResult
+$Res call({
+ String id, String nameDe, String nameEn
+});
+
+
+
+
+}
+/// @nodoc
+class __$CatalogTermCopyWithImpl<$Res>
+    implements _$CatalogTermCopyWith<$Res> {
+  __$CatalogTermCopyWithImpl(this._self, this._then);
+
+  final _CatalogTerm _self;
+  final $Res Function(_CatalogTerm) _then;
+
+/// Create a copy of CatalogTerm
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? id = null,Object? nameDe = null,Object? nameEn = null,}) {
+  return _then(_CatalogTerm(
+id: null == id ? _self.id : id // ignore: cast_nullable_to_non_nullable
+as String,nameDe: null == nameDe ? _self.nameDe : nameDe // ignore: cast_nullable_to_non_nullable
+as String,nameEn: null == nameEn ? _self.nameEn : nameEn // ignore: cast_nullable_to_non_nullable
+as String,
+  ));
+}
+
+
+}
+
+// dart format on

app/lib/features/catalog/presentation/catalog_query_params.dart

@@ -0,0 +1,90 @@
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+
+/// Query parameter names of `/catalog` (Spec #3 § 5.5).
+abstract final class CatalogQueryParams {
+  static const text = 'q';
+  static const players = 'players';
+  static const maxMinutes = 'maxMinutes';
+  static const age = 'age';
+  static const genre = 'genre';
+  static const mechanic = 'mechanic';
+}
+
+final _uuid = RegExp(
+  r'^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-'
+  r'[0-9a-fA-F]{12}$',
+);
+
+/// Reads a search from URL parameters. Invalid or unknown values are ignored
+/// silently (Spec #3 § 5.5): numbers must be allowed values, IDs must look
+/// like UUIDs, at most 20 IDs per kind.
+CatalogSearchQuery parseCatalogQuery(Map<String, String> params) {
+  int? number(String key, bool Function(int) allowed) {
+    final value = int.tryParse(params[key] ?? '');
+    return value != null && allowed(value) ? value : null;
+  }
+
+  Set<String> ids(String key) {
+    final raw = params[key];
+    if (raw == null || raw.isEmpty) {
+      return const {};
+    }
+    final result = <String>{};
+    for (final part in raw.split(',')) {
+      final id = part.trim().toLowerCase();
+      if (_uuid.hasMatch(id) && result.length < CatalogSearchLimits.maxTerms) {
+        result.add(id);
+      }
+    }
+    return result;
+  }
+
+  return CatalogSearchQuery(
+    text: CatalogSearchQuery.cleanText(params[CatalogQueryParams.text] ?? ''),
+    filters: CatalogFilters(
+      players: number(
+        CatalogQueryParams.players,
+        (v) =>
+            v >= CatalogSearchLimits.minPlayers &&
+            v <= CatalogSearchLimits.maxPlayers,
+      ),
+      maxMinutes: number(
+        CatalogQueryParams.maxMinutes,
+        CatalogSearchLimits.maxMinutesSteps.contains,
+      ),
+      minAgeSuitable: number(
+        CatalogQueryParams.age,
+        CatalogSearchLimits.ageSteps.contains,
+      ),
+      genreIds: ids(CatalogQueryParams.genre),
+      mechanicIds: ids(CatalogQueryParams.mechanic),
+    ),
+  );
+}
+
+/// The URL parameters of [query]; only set values (inverse of
+/// [parseCatalogQuery]).
+Map<String, String> catalogQueryParameters(CatalogSearchQuery query) {
+  final filters = query.filters;
+  return {
+    if (query.text.isNotEmpty) CatalogQueryParams.text: query.text,
+    if (filters.players != null)
+      CatalogQueryParams.players: '${filters.players}',
+    if (filters.maxMinutes != null)
+      CatalogQueryParams.maxMinutes: '${filters.maxMinutes}',
+    if (filters.minAgeSuitable != null)
+      CatalogQueryParams.age: '${filters.minAgeSuitable}',
+    if (filters.genreIds.isNotEmpty)
+      CatalogQueryParams.genre: (filters.genreIds.toList()..sort()).join(','),
+    if (filters.mechanicIds.isNotEmpty)
+      CatalogQueryParams.mechanic: (filters.mechanicIds.toList()..sort()).join(
+        ',',
+      ),
+  };
+}
+
+/// The `/catalog` location (path plus query) of [query].
+Uri catalogLocation(String path, CatalogSearchQuery query) {
+  final params = catalogQueryParameters(query);
+  return Uri(path: path, queryParameters: params.isEmpty ? null : params);
+}

app/lib/features/catalog/presentation/catalog_routes.dart

@@ -0,0 +1,19 @@
+import 'package:go_router/go_router.dart';
+import 'package:shuffle/core/routing/app_routes.dart';
+import 'package:shuffle/features/catalog/presentation/catalog_query_params.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_screen.dart';
+
+/// Routes of the catalog (Spec #3 § 5.5). `/catalog` is public.
+///
+/// These are sub-routes of the start page (path `catalog` below `/`), so the
+/// URL stays `/catalog`, but a deep link builds the stack [home, catalog] and
+/// the system back button (Android) returns to the start page instead of
+/// closing the app.
+final List<RouteBase> catalogRoutes = [
+  GoRoute(
+    path: AppRoutes.catalogSegment,
+    builder: (context, state) => CatalogSearchScreen(
+      initialQuery: parseCatalogQuery(state.uri.queryParameters),
+    ),
+  ),
+];

app/lib/features/catalog/presentation/providers/catalog_providers.dart

@@ -0,0 +1,28 @@
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:shuffle/core/supabase/supabase_client_provider.dart';
+import 'package:shuffle/features/catalog/data/supabase_catalog_repository.dart';
+import 'package:shuffle/features/catalog/domain/catalog_repository.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+
+part 'catalog_providers.g.dart';
+
+Duration? _noRetry(int retryCount, Object error) => null;
+
+@Riverpod(keepAlive: true)
+CatalogRepository catalogRepository(Ref ref) =>
+    SupabaseCatalogRepository(ref.watch(supabaseClientProvider));
+
+/// Genres for the filter. Without automatic retry: the filter area offers an
+/// explicit "try again" and the rest of the search stays usable.
+@Riverpod(keepAlive: true, retry: _noRetry)
+Future<List<CatalogTerm>> catalogGenres(Ref ref) async {
+  final result = await ref.watch(catalogRepositoryProvider).fetchGenres();
+  return result.when(success: (terms) => terms, failure: (f) => throw f);
+}
+
+/// Mechanics for the filter, see [catalogGenres].
+@Riverpod(keepAlive: true, retry: _noRetry)
+Future<List<CatalogTerm>> catalogMechanics(Ref ref) async {
+  final result = await ref.watch(catalogRepositoryProvider).fetchMechanics();
+  return result.when(success: (terms) => terms, failure: (f) => throw f);
+}

app/lib/features/catalog/presentation/providers/catalog_providers.g.dart

@@ -0,0 +1,152 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'catalog_providers.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint, type=warning
+
+@ProviderFor(catalogRepository)
+final catalogRepositoryProvider = CatalogRepositoryProvider._();
+
+final class CatalogRepositoryProvider
+    extends
+        $FunctionalProvider<
+          CatalogRepository,
+          CatalogRepository,
+          CatalogRepository
+        >
+    with $Provider<CatalogRepository> {
+  CatalogRepositoryProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: null,
+        name: r'catalogRepositoryProvider',
+        isAutoDispose: false,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$catalogRepositoryHash();
+
+  @$internal
+  @override
+  $ProviderElement<CatalogRepository> $createElement(
+    $ProviderPointer pointer,
+  ) => $ProviderElement(pointer);
+
+  @override
+  CatalogRepository create(Ref ref) {
+    return catalogRepository(ref);
+  }
+
+  /// {@macro riverpod.override_with_value}
+  Override overrideWithValue(CatalogRepository value) {
+    return $ProviderOverride(
+      origin: this,
+      providerOverride: $SyncValueProvider<CatalogRepository>(value),
+    );
+  }
+}
+
+String _$catalogRepositoryHash() => r'20e0557d699468ce4d1db2a740352fdab045cc9e';
+
+/// Genres for the filter. Without automatic retry: the filter area offers an
+/// explicit "try again" and the rest of the search stays usable.
+
+@ProviderFor(catalogGenres)
+final catalogGenresProvider = CatalogGenresProvider._();
+
+/// Genres for the filter. Without automatic retry: the filter area offers an
+/// explicit "try again" and the rest of the search stays usable.
+
+final class CatalogGenresProvider
+    extends
+        $FunctionalProvider<
+          AsyncValue<List<CatalogTerm>>,
+          List<CatalogTerm>,
+          FutureOr<List<CatalogTerm>>
+        >
+    with
+        $FutureModifier<List<CatalogTerm>>,
+        $FutureProvider<List<CatalogTerm>> {
+  /// Genres for the filter. Without automatic retry: the filter area offers an
+  /// explicit "try again" and the rest of the search stays usable.
+  CatalogGenresProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: _noRetry,
+        name: r'catalogGenresProvider',
+        isAutoDispose: false,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$catalogGenresHash();
+
+  @$internal
+  @override
+  $FutureProviderElement<List<CatalogTerm>> $createElement(
+    $ProviderPointer pointer,
+  ) => $FutureProviderElement(pointer);
+
+  @override
+  FutureOr<List<CatalogTerm>> create(Ref ref) {
+    return catalogGenres(ref);
+  }
+}
+
+String _$catalogGenresHash() => r'c04134a33952ff3d30818d557ed03418447cdd25';
+
+/// Mechanics for the filter, see [catalogGenres].
+
+@ProviderFor(catalogMechanics)
+final catalogMechanicsProvider = CatalogMechanicsProvider._();
+
+/// Mechanics for the filter, see [catalogGenres].
+
+final class CatalogMechanicsProvider
+    extends
+        $FunctionalProvider<
+          AsyncValue<List<CatalogTerm>>,
+          List<CatalogTerm>,
+          FutureOr<List<CatalogTerm>>
+        >
+    with
+        $FutureModifier<List<CatalogTerm>>,
+        $FutureProvider<List<CatalogTerm>> {
+  /// Mechanics for the filter, see [catalogGenres].
+  CatalogMechanicsProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: _noRetry,
+        name: r'catalogMechanicsProvider',
+        isAutoDispose: false,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$catalogMechanicsHash();
+
+  @$internal
+  @override
+  $FutureProviderElement<List<CatalogTerm>> $createElement(
+    $ProviderPointer pointer,
+  ) => $FutureProviderElement(pointer);
+
+  @override
+  FutureOr<List<CatalogTerm>> create(Ref ref) {
+    return catalogMechanics(ref);
+  }
+}
+
+String _$catalogMechanicsHash() => r'4a7b95bb44d3aa59748754e55b4802b9bf16c44c';

app/lib/features/catalog/presentation/search/catalog_search_controller.dart

@@ -0,0 +1,190 @@
+import 'dart:async';
+
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/providers/catalog_providers.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_state.dart';
+
+part 'catalog_search_controller.g.dart';
+
+/// Debounce between the last keystroke and the search (Spec #3 § 5.4).
+const catalogSearchDebounce = Duration(milliseconds: 300);
+
+/// Logic of the catalog search: debounce, only the latest request counts,
+/// paging, retry (KAT-01 criteria 1, 4, 5, 8).
+@riverpod
+class CatalogSearchController extends _$CatalogSearchController {
+  Timer? _debounce;
+  int _requestId = 0;
+  bool _initialized = false;
+
+  /// The effective query of the latest started first-page search, to skip
+  /// searches that would repeat it.
+  CatalogSearchQuery? _lastRequested;
+
+  @override
+  CatalogSearchState build() {
+    ref.onDispose(() => _debounce?.cancel());
+    return const CatalogSearchState();
+  }
+
+  /// Opens the screen with [initial] (from the URL) and searches right away.
+  /// Does nothing when called again.
+  void init(CatalogSearchQuery initial) {
+    if (_initialized) {
+      return;
+    }
+    _initialized = true;
+    state = state.copyWith(query: initial);
+    unawaited(_search());
+  }
+
+  /// Text changed: search after the debounce. A text below the minimum
+  /// length counts as "no search term".
+  void setText(String raw) {
+    final text = CatalogSearchQuery.cleanText(raw);
+    if (text == state.query.text) {
+      return;
+    }
+    state = state.copyWith(query: state.query.copyWith(text: text));
+    _debounce?.cancel();
+    _debounce = Timer(catalogSearchDebounce, () => unawaited(_search()));
+  }
+
+  /// Enter in the search field: search now, without debounce.
+  void submitText(String raw) {
+    _debounce?.cancel();
+    final text = CatalogSearchQuery.cleanText(raw);
+    state = state.copyWith(query: state.query.copyWith(text: text));
+    unawaited(_search(force: true));
+  }
+
+  /// Filters changed: search now (a pending debounce is executed with it).
+  void setFilters(CatalogFilters filters) {
+    _debounce?.cancel();
+    state = state.copyWith(query: state.query.copyWith(filters: filters));
+    unawaited(_search());
+  }
+
+  /// Drops genre IDs (from the URL) that are not in the vocabulary [known].
+  /// Searches again only if something was removed.
+  void retainKnownGenres(Set<String> known) {
+    final filters = state.query.filters;
+    final kept = filters.genreIds.where(known.contains).toSet();
+    if (kept.length != filters.genreIds.length) {
+      setFilters(filters.copyWith(genreIds: kept));
+    }
+  }
+
+  /// Like [retainKnownGenres] for mechanics.
+  void retainKnownMechanics(Set<String> known) {
+    final filters = state.query.filters;
+    final kept = filters.mechanicIds.where(known.contains).toSet();
+    if (kept.length != filters.mechanicIds.length) {
+      setFilters(filters.copyWith(mechanicIds: kept));
+    }
+  }
+
+  void clearFilters() => setFilters(const CatalogFilters());
+
+  /// Loads the next page of the shown results.
+  Future<void> loadMore() async {
+    if (state.status != CatalogSearchStatus.data ||
+        !state.hasMore ||
+        state.loadingMore ||
+        state.refreshing) {
+      return;
+    }
+    final id = ++_requestId;
+    final offset = state.items.length;
+    state = state.copyWith(loadingMore: true, loadMoreFailure: null);
+    final result = await ref
+        .read(catalogRepositoryProvider)
+        .search(state.searchedQuery, offset: offset);
+    if (!ref.mounted || id != _requestId) {
+      return;
+    }
+    result.when(
+      success: (page) {
+        final known = {for (final item in state.items) item.id};
+        final added = [
+          for (final item in page.items)
+            if (known.add(item.id)) item,
+        ];
+        final items = [...state.items, ...added];
+        state = state.copyWith(
+          items: items,
+          // An empty or fully repeated page ends the list, so automatic
+          // loading cannot spin on the same offset.
+          totalCount: added.isEmpty ? items.length : page.totalCount,
+          loadingMore: false,
+        );
+      },
+      failure: (failure) {
+        state = state.copyWith(loadingMore: false, loadMoreFailure: failure);
+      },
+    );
+  }
+
+  /// Repeats the last failed action (first page or next page).
+  Future<void> retry() async {
+    if (state.status == CatalogSearchStatus.error) {
+      await _search(force: true);
+    } else if (state.loadMoreFailure != null) {
+      state = state.copyWith(loadMoreFailure: null);
+      await loadMore();
+    }
+  }
+
+  Future<void> _search({bool force = false}) async {
+    final query = state.query;
+    final effective = query.effective;
+    if (!force &&
+        _lastRequested == effective &&
+        state.status != CatalogSearchStatus.error) {
+      return;
+    }
+    _lastRequested = effective;
+    final id = ++_requestId;
+    final hasItems = state.items.isNotEmpty;
+    state = state.copyWith(
+      status: hasItems ? state.status : CatalogSearchStatus.loading,
+      refreshing: hasItems,
+      failure: null,
+      loadingMore: false,
+      loadMoreFailure: null,
+    );
+    final result = await ref
+        .read(catalogRepositoryProvider)
+        .search(effective, offset: 0);
+    if (!ref.mounted || id != _requestId) {
+      return;
+    }
+    result.when(
+      success: (page) {
+        state = state.copyWith(
+          status: page.items.isEmpty
+              ? CatalogSearchStatus.empty
+              : CatalogSearchStatus.data,
+          items: page.items,
+          totalCount: page.totalCount,
+          searchedQuery: query,
+          refreshing: false,
+          failure: null,
+          searchGeneration: state.searchGeneration + 1,
+        );
+      },
+      failure: (failure) {
+        // Keep the entered query so the user can retry.
+        _lastRequested = null;
+        state = state.copyWith(
+          status: CatalogSearchStatus.error,
+          items: const [],
+          totalCount: 0,
+          refreshing: false,
+          failure: failure,
+        );
+      },
+    );
+  }
+}

app/lib/features/catalog/presentation/search/catalog_search_controller.g.dart

@@ -0,0 +1,72 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'catalog_search_controller.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint, type=warning
+/// Logic of the catalog search: debounce, only the latest request counts,
+/// paging, retry (KAT-01 criteria 1, 4, 5, 8).
+
+@ProviderFor(CatalogSearchController)
+final catalogSearchControllerProvider = CatalogSearchControllerProvider._();
+
+/// Logic of the catalog search: debounce, only the latest request counts,
+/// paging, retry (KAT-01 criteria 1, 4, 5, 8).
+final class CatalogSearchControllerProvider
+    extends $NotifierProvider<CatalogSearchController, CatalogSearchState> {
+  /// Logic of the catalog search: debounce, only the latest request counts,
+  /// paging, retry (KAT-01 criteria 1, 4, 5, 8).
+  CatalogSearchControllerProvider._()
+    : super(
+        from: null,
+        argument: null,
+        retry: null,
+        name: r'catalogSearchControllerProvider',
+        isAutoDispose: true,
+        dependencies: null,
+        $allTransitiveDependencies: null,
+      );
+
+  @override
+  String debugGetCreateSourceHash() => _$catalogSearchControllerHash();
+
+  @$internal
+  @override
+  CatalogSearchController create() => CatalogSearchController();
+
+  /// {@macro riverpod.override_with_value}
+  Override overrideWithValue(CatalogSearchState value) {
+    return $ProviderOverride(
+      origin: this,
+      providerOverride: $SyncValueProvider<CatalogSearchState>(value),
+    );
+  }
+}
+
+String _$catalogSearchControllerHash() =>
+    r'e75dae20e21a2595e02dd79004172f34c90ba90c';
+
+/// Logic of the catalog search: debounce, only the latest request counts,
+/// paging, retry (KAT-01 criteria 1, 4, 5, 8).
+
+abstract class _$CatalogSearchController extends $Notifier<CatalogSearchState> {
+  CatalogSearchState build();
+  @$mustCallSuper
+  @override
+  WhenComplete runBuild() {
+    final ref = this.ref as $Ref<CatalogSearchState, CatalogSearchState>;
+    final element =
+        ref.element
+            as $ClassProviderElement<
+              AnyNotifier<CatalogSearchState, CatalogSearchState>,
+              CatalogSearchState,
+              Object?,
+              Object?
+            >;
+    return element.handleCreate(ref, build);
+  }
+}

app/lib/features/catalog/presentation/search/catalog_search_screen.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/routing/app_routes.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_view.dart';
+
+/// Screen of the catalog search (`/catalog`, public, Spec #3 § 5.5).
+class CatalogSearchScreen extends StatelessWidget {
+  const CatalogSearchScreen({
+    required this.initialQuery,
+    super.key,
+    this.onReportGame,
+  });
+
+  /// Start values from the URL.
+  final CatalogSearchQuery initialQuery;
+
+  /// Entry point to report a missing game (KAT-04, #13); `null` in #3.
+  final ValueChanged<String>? onReportGame;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      key: const Key('catalog_search_screen'),
+      appBar: AppBar(
+        leading: BackButton(
+          onPressed: () =>
+              context.canPop() ? context.pop() : context.go(AppRoutes.home),
+        ),
+        title: Text(context.l10n.catalogSearchTitle),
+      ),
+      body: CatalogSearchView(
+        initialQuery: initialQuery,
+        onReportGame: onReportGame,
+        syncUrl: true,
+      ),
+    );
+  }
+}

app/lib/features/catalog/presentation/search/catalog_search_state.dart

@@ -0,0 +1,38 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_game_summary.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+
+part 'catalog_search_state.freezed.dart';
+
+enum CatalogSearchStatus { loading, data, empty, error }
+
+/// State of the catalog search (Spec #3 § 5.4).
+@freezed
+abstract class CatalogSearchState with _$CatalogSearchState {
+  const factory CatalogSearchState({
+    /// What the user entered. May be ahead of the shown results while a
+    /// search is debounced or running.
+    @Default(CatalogSearchQuery()) CatalogSearchQuery query,
+
+    /// The query the shown results belong to.
+    @Default(CatalogSearchQuery()) CatalogSearchQuery searchedQuery,
+    @Default(CatalogSearchStatus.loading) CatalogSearchStatus status,
+    @Default(<CatalogGameSummary>[]) List<CatalogGameSummary> items,
+    @Default(0) int totalCount,
+    CatalogFailure? failure,
+
+    /// A new search runs while the old results stay visible.
+    @Default(false) bool refreshing,
+    @Default(false) bool loadingMore,
+    CatalogFailure? loadMoreFailure,
+
+    /// Counts completed first-page searches (announcements, URL sync).
+    @Default(0) int searchGeneration,
+  }) = _CatalogSearchState;
+
+  const CatalogSearchState._();
+
+  bool get hasMore =>
+      items.length < totalCount && items.length < CatalogSearchLimits.maxOffset;
+}

app/lib/features/catalog/presentation/search/catalog_search_state.freezed.dart

@@ -0,0 +1,406 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// coverage:ignore-file
+// ignore_for_file: type=lint, type=warning, deprecated_member_use, deprecated_member_use_from_same_package
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'catalog_search_state.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// dart format off
+T _$identity<T>(T value) => value;
+/// @nodoc
+mixin _$CatalogSearchState {
+
+/// What the user entered. May be ahead of the shown results while a
+/// search is debounced or running.
+ CatalogSearchQuery get query;/// The query the shown results belong to.
+ CatalogSearchQuery get searchedQuery; CatalogSearchStatus get status; List<CatalogGameSummary> get items; int get totalCount; CatalogFailure? get failure;/// A new search runs while the old results stay visible.
+ bool get refreshing; bool get loadingMore; CatalogFailure? get loadMoreFailure;/// Counts completed first-page searches (announcements, URL sync).
+ int get searchGeneration;
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+$CatalogSearchStateCopyWith<CatalogSearchState> get copyWith => _$CatalogSearchStateCopyWithImpl<CatalogSearchState>(this as CatalogSearchState, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+  final _this = this as CatalogSearchState;
+  return identical(this, other) || (other.runtimeType == runtimeType&&other is CatalogSearchState&&(identical(other.query, _this.query) || other.query == _this.query)&&(identical(other.searchedQuery, _this.searchedQuery) || other.searchedQuery == _this.searchedQuery)&&(identical(other.status, _this.status) || other.status == _this.status)&&const DeepCollectionEquality().equals(other.items, _this.items)&&(identical(other.totalCount, _this.totalCount) || other.totalCount == _this.totalCount)&&(identical(other.failure, _this.failure) || other.failure == _this.failure)&&(identical(other.refreshing, _this.refreshing) || other.refreshing == _this.refreshing)&&(identical(other.loadingMore, _this.loadingMore) || other.loadingMore == _this.loadingMore)&&(identical(other.loadMoreFailure, _this.loadMoreFailure) || other.loadMoreFailure == _this.loadMoreFailure)&&(identical(other.searchGeneration, _this.searchGeneration) || other.searchGeneration == _this.searchGeneration));
+}
+
+
+@override
+int get hashCode {
+  final _this = this as CatalogSearchState;
+  return Object.hash(runtimeType,_this.query,_this.searchedQuery,_this.status,const DeepCollectionEquality().hash(_this.items),_this.totalCount,_this.failure,_this.refreshing,_this.loadingMore,_this.loadMoreFailure,_this.searchGeneration);
+}
+
+@override
+String toString() {
+  final _this = this as CatalogSearchState;
+  return 'CatalogSearchState(query: ${_this.query}, searchedQuery: ${_this.searchedQuery}, status: ${_this.status}, items: ${_this.items}, totalCount: ${_this.totalCount}, failure: ${_this.failure}, refreshing: ${_this.refreshing}, loadingMore: ${_this.loadingMore}, loadMoreFailure: ${_this.loadMoreFailure}, searchGeneration: ${_this.searchGeneration})';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class $CatalogSearchStateCopyWith<$Res>  {
+  factory $CatalogSearchStateCopyWith(CatalogSearchState value, $Res Function(CatalogSearchState) _then) = _$CatalogSearchStateCopyWithImpl;
+@useResult
+$Res call({
+ CatalogSearchQuery query, CatalogSearchQuery searchedQuery, CatalogSearchStatus status, List<CatalogGameSummary> items, int totalCount, CatalogFailure? failure, bool refreshing, bool loadingMore, CatalogFailure? loadMoreFailure, int searchGeneration
+});
+
+
+$CatalogSearchQueryCopyWith<$Res> get query;$CatalogSearchQueryCopyWith<$Res> get searchedQuery;$CatalogFailureCopyWith<$Res>? get failure;$CatalogFailureCopyWith<$Res>? get loadMoreFailure;
+
+}
+/// @nodoc
+class _$CatalogSearchStateCopyWithImpl<$Res>
+    implements $CatalogSearchStateCopyWith<$Res> {
+  _$CatalogSearchStateCopyWithImpl(this._self, this._then);
+
+  final CatalogSearchState _self;
+  final $Res Function(CatalogSearchState) _then;
+
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@pragma('vm:prefer-inline') @override $Res call({Object? query = null,Object? searchedQuery = null,Object? status = null,Object? items = null,Object? totalCount = null,Object? failure = freezed,Object? refreshing = null,Object? loadingMore = null,Object? loadMoreFailure = freezed,Object? searchGeneration = null,}) {
+  return _then(CatalogSearchState(
+query: null == query ? _self.query : query // ignore: cast_nullable_to_non_nullable
+as CatalogSearchQuery,searchedQuery: null == searchedQuery ? _self.searchedQuery : searchedQuery // ignore: cast_nullable_to_non_nullable
+as CatalogSearchQuery,status: null == status ? _self.status : status // ignore: cast_nullable_to_non_nullable
+as CatalogSearchStatus,items: null == items ? _self.items : items // ignore: cast_nullable_to_non_nullable
+as List<CatalogGameSummary>,totalCount: null == totalCount ? _self.totalCount : totalCount // ignore: cast_nullable_to_non_nullable
+as int,failure: freezed == failure ? _self.failure : failure // ignore: cast_nullable_to_non_nullable
+as CatalogFailure?,refreshing: null == refreshing ? _self.refreshing : refreshing // ignore: cast_nullable_to_non_nullable
+as bool,loadingMore: null == loadingMore ? _self.loadingMore : loadingMore // ignore: cast_nullable_to_non_nullable
+as bool,loadMoreFailure: freezed == loadMoreFailure ? _self.loadMoreFailure : loadMoreFailure // ignore: cast_nullable_to_non_nullable
+as CatalogFailure?,searchGeneration: null == searchGeneration ? _self.searchGeneration : searchGeneration // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogSearchQueryCopyWith<$Res> get query {
+  
+  return $CatalogSearchQueryCopyWith<$Res>(_self.query, (value) {
+    return _then(_self.copyWith(query: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogSearchQueryCopyWith<$Res> get searchedQuery {
+  
+  return $CatalogSearchQueryCopyWith<$Res>(_self.searchedQuery, (value) {
+    return _then(_self.copyWith(searchedQuery: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFailureCopyWith<$Res>? get failure {
+    if (_self.failure == null) {
+    return null;
+  }
+
+  return $CatalogFailureCopyWith<$Res>(_self.failure!, (value) {
+    return _then(_self.copyWith(failure: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFailureCopyWith<$Res>? get loadMoreFailure {
+    if (_self.loadMoreFailure == null) {
+    return null;
+  }
+
+  return $CatalogFailureCopyWith<$Res>(_self.loadMoreFailure!, (value) {
+    return _then(_self.copyWith(loadMoreFailure: value));
+  });
+}
+}
+
+
+/// Adds pattern-matching-related methods to [CatalogSearchState].
+extension CatalogSearchStatePatterns on CatalogSearchState {
+/// A variant of `map` that fallback to returning `orElse`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeMap<TResult extends Object?>(TResult Function( _CatalogSearchState value)?  $default,{required TResult orElse(),}){
+final _that = this;
+switch (_that) {
+case _CatalogSearchState() when $default != null:
+return $default(_that);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// Callbacks receives the raw object, upcasted.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case final Subclass2 value:
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult map<TResult extends Object?>(TResult Function( _CatalogSearchState value)  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchState():
+return $default(_that);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `map` that fallback to returning `null`.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case final Subclass value:
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>(TResult? Function( _CatalogSearchState value)?  $default,){
+final _that = this;
+switch (_that) {
+case _CatalogSearchState() when $default != null:
+return $default(_that);case _:
+  return null;
+
+}
+}
+/// A variant of `when` that fallback to an `orElse` callback.
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return orElse();
+/// }
+/// ```
+
+@optionalTypeArgs TResult maybeWhen<TResult extends Object?>(TResult Function( CatalogSearchQuery query,  CatalogSearchQuery searchedQuery,  CatalogSearchStatus status,  List<CatalogGameSummary> items,  int totalCount,  CatalogFailure? failure,  bool refreshing,  bool loadingMore,  CatalogFailure? loadMoreFailure,  int searchGeneration)?  $default,{required TResult orElse(),}) {final _that = this;
+switch (_that) {
+case _CatalogSearchState() when $default != null:
+return $default(_that.query,_that.searchedQuery,_that.status,_that.items,_that.totalCount,_that.failure,_that.refreshing,_that.loadingMore,_that.loadMoreFailure,_that.searchGeneration);case _:
+  return orElse();
+
+}
+}
+/// A `switch`-like method, using callbacks.
+///
+/// As opposed to `map`, this offers destructuring.
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case Subclass2(:final field2):
+///     return ...;
+/// }
+/// ```
+
+@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( CatalogSearchQuery query,  CatalogSearchQuery searchedQuery,  CatalogSearchStatus status,  List<CatalogGameSummary> items,  int totalCount,  CatalogFailure? failure,  bool refreshing,  bool loadingMore,  CatalogFailure? loadMoreFailure,  int searchGeneration)  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchState():
+return $default(_that.query,_that.searchedQuery,_that.status,_that.items,_that.totalCount,_that.failure,_that.refreshing,_that.loadingMore,_that.loadMoreFailure,_that.searchGeneration);case _:
+  throw StateError('Unexpected subclass');
+
+}
+}
+/// A variant of `when` that fallback to returning `null`
+///
+/// It is equivalent to doing:
+/// ```dart
+/// switch (sealedClass) {
+///   case Subclass(:final field):
+///     return ...;
+///   case _:
+///     return null;
+/// }
+/// ```
+
+@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( CatalogSearchQuery query,  CatalogSearchQuery searchedQuery,  CatalogSearchStatus status,  List<CatalogGameSummary> items,  int totalCount,  CatalogFailure? failure,  bool refreshing,  bool loadingMore,  CatalogFailure? loadMoreFailure,  int searchGeneration)?  $default,) {final _that = this;
+switch (_that) {
+case _CatalogSearchState() when $default != null:
+return $default(_that.query,_that.searchedQuery,_that.status,_that.items,_that.totalCount,_that.failure,_that.refreshing,_that.loadingMore,_that.loadMoreFailure,_that.searchGeneration);case _:
+  return null;
+
+}
+}
+
+}
+
+/// @nodoc
+
+
+class _CatalogSearchState extends CatalogSearchState {
+  const _CatalogSearchState({this.query = const CatalogSearchQuery(), this.searchedQuery = const CatalogSearchQuery(), this.status = CatalogSearchStatus.loading,  List<CatalogGameSummary> items = const <CatalogGameSummary>[], this.totalCount = 0, this.failure, this.refreshing = false, this.loadingMore = false, this.loadMoreFailure, this.searchGeneration = 0}): _items = items,super._();
+  
+
+/// What the user entered. May be ahead of the shown results while a
+/// search is debounced or running.
+@override@JsonKey() final  CatalogSearchQuery query;
+/// The query the shown results belong to.
+@override@JsonKey() final  CatalogSearchQuery searchedQuery;
+@override@JsonKey() final  CatalogSearchStatus status;
+ final  List<CatalogGameSummary> _items;
+@override@JsonKey() List<CatalogGameSummary> get items {
+  if (_items is EqualUnmodifiableListView) return _items;
+  // ignore: implicit_dynamic_type
+  return EqualUnmodifiableListView(_items);
+}
+
+@override@JsonKey() final  int totalCount;
+@override final  CatalogFailure? failure;
+/// A new search runs while the old results stay visible.
+@override@JsonKey() final  bool refreshing;
+@override@JsonKey() final  bool loadingMore;
+@override final  CatalogFailure? loadMoreFailure;
+/// Counts completed first-page searches (announcements, URL sync).
+@override@JsonKey() final  int searchGeneration;
+
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override @JsonKey(includeFromJson: false, includeToJson: false)
+@pragma('vm:prefer-inline')
+_$CatalogSearchStateCopyWith<_CatalogSearchState> get copyWith => __$CatalogSearchStateCopyWithImpl<_CatalogSearchState>(this, _$identity);
+
+
+
+@override
+bool operator ==(Object other) {
+    return identical(this, other) || (other.runtimeType == runtimeType&&other is _CatalogSearchState&&(identical(other.query, query) || other.query == query)&&(identical(other.searchedQuery, searchedQuery) || other.searchedQuery == searchedQuery)&&(identical(other.status, status) || other.status == status)&&const DeepCollectionEquality().equals(other.items, _items)&&(identical(other.totalCount, totalCount) || other.totalCount == totalCount)&&(identical(other.failure, failure) || other.failure == failure)&&(identical(other.refreshing, refreshing) || other.refreshing == refreshing)&&(identical(other.loadingMore, loadingMore) || other.loadingMore == loadingMore)&&(identical(other.loadMoreFailure, loadMoreFailure) || other.loadMoreFailure == loadMoreFailure)&&(identical(other.searchGeneration, searchGeneration) || other.searchGeneration == searchGeneration));
+}
+
+
+@override
+int get hashCode {
+    return Object.hash(runtimeType,query,searchedQuery,status,const DeepCollectionEquality().hash(_items),totalCount,failure,refreshing,loadingMore,loadMoreFailure,searchGeneration);
+}
+
+@override
+String toString() {
+    return 'CatalogSearchState(query: $query, searchedQuery: $searchedQuery, status: $status, items: $items, totalCount: $totalCount, failure: $failure, refreshing: $refreshing, loadingMore: $loadingMore, loadMoreFailure: $loadMoreFailure, searchGeneration: $searchGeneration)';
+}
+
+
+}
+
+/// @nodoc
+abstract mixin class _$CatalogSearchStateCopyWith<$Res> implements $CatalogSearchStateCopyWith<$Res> {
+  factory _$CatalogSearchStateCopyWith(_CatalogSearchState value, $Res Function(_CatalogSearchState) _then) = __$CatalogSearchStateCopyWithImpl;
+@override @useResult
+$Res call({
+ CatalogSearchQuery query, CatalogSearchQuery searchedQuery, CatalogSearchStatus status, List<CatalogGameSummary> items, int totalCount, CatalogFailure? failure, bool refreshing, bool loadingMore, CatalogFailure? loadMoreFailure, int searchGeneration
+});
+
+
+@override $CatalogSearchQueryCopyWith<$Res> get query;@override $CatalogSearchQueryCopyWith<$Res> get searchedQuery;@override $CatalogFailureCopyWith<$Res>? get failure;@override $CatalogFailureCopyWith<$Res>? get loadMoreFailure;
+
+}
+/// @nodoc
+class __$CatalogSearchStateCopyWithImpl<$Res>
+    implements _$CatalogSearchStateCopyWith<$Res> {
+  __$CatalogSearchStateCopyWithImpl(this._self, this._then);
+
+  final _CatalogSearchState _self;
+  final $Res Function(_CatalogSearchState) _then;
+
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override @pragma('vm:prefer-inline') $Res call({Object? query = null,Object? searchedQuery = null,Object? status = null,Object? items = null,Object? totalCount = null,Object? failure = freezed,Object? refreshing = null,Object? loadingMore = null,Object? loadMoreFailure = freezed,Object? searchGeneration = null,}) {
+  return _then(_CatalogSearchState(
+query: null == query ? _self.query : query // ignore: cast_nullable_to_non_nullable
+as CatalogSearchQuery,searchedQuery: null == searchedQuery ? _self.searchedQuery : searchedQuery // ignore: cast_nullable_to_non_nullable
+as CatalogSearchQuery,status: null == status ? _self.status : status // ignore: cast_nullable_to_non_nullable
+as CatalogSearchStatus,items: null == items ? _self._items : items // ignore: cast_nullable_to_non_nullable
+as List<CatalogGameSummary>,totalCount: null == totalCount ? _self.totalCount : totalCount // ignore: cast_nullable_to_non_nullable
+as int,failure: freezed == failure ? _self.failure : failure // ignore: cast_nullable_to_non_nullable
+as CatalogFailure?,refreshing: null == refreshing ? _self.refreshing : refreshing // ignore: cast_nullable_to_non_nullable
+as bool,loadingMore: null == loadingMore ? _self.loadingMore : loadingMore // ignore: cast_nullable_to_non_nullable
+as bool,loadMoreFailure: freezed == loadMoreFailure ? _self.loadMoreFailure : loadMoreFailure // ignore: cast_nullable_to_non_nullable
+as CatalogFailure?,searchGeneration: null == searchGeneration ? _self.searchGeneration : searchGeneration // ignore: cast_nullable_to_non_nullable
+as int,
+  ));
+}
+
+/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogSearchQueryCopyWith<$Res> get query {
+  
+  return $CatalogSearchQueryCopyWith<$Res>(_self.query, (value) {
+    return _then(_self.copyWith(query: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogSearchQueryCopyWith<$Res> get searchedQuery {
+  
+  return $CatalogSearchQueryCopyWith<$Res>(_self.searchedQuery, (value) {
+    return _then(_self.copyWith(searchedQuery: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFailureCopyWith<$Res>? get failure {
+    if (_self.failure == null) {
+    return null;
+  }
+
+  return $CatalogFailureCopyWith<$Res>(_self.failure!, (value) {
+    return _then(_self.copyWith(failure: value));
+  });
+}/// Create a copy of CatalogSearchState
+/// with the given fields replaced by the non-null parameter values.
+@override
+@pragma('vm:prefer-inline')
+$CatalogFailureCopyWith<$Res>? get loadMoreFailure {
+    if (_self.loadMoreFailure == null) {
+    return null;
+  }
+
+  return $CatalogFailureCopyWith<$Res>(_self.loadMoreFailure!, (value) {
+    return _then(_self.copyWith(loadMoreFailure: value));
+  });
+}
+}
+
+// dart format on

app/lib/features/catalog/presentation/search/catalog_search_view.dart

@@ -0,0 +1,525 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/semantics.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/routing/app_routes.dart';
+import 'package:shuffle/core/routing/url_replacer.dart';
+import 'package:shuffle/core/theme/app_spacing.dart';
+import 'package:shuffle/core/widgets/app_list_footer.dart';
+import 'package:shuffle/core/widgets/app_state_message.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+import 'package:shuffle/features/catalog/presentation/catalog_query_params.dart';
+import 'package:shuffle/features/catalog/presentation/providers/catalog_providers.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_controller.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_state.dart';
+import 'package:shuffle/features/catalog/presentation/search/widgets/catalog_empty_state.dart';
+import 'package:shuffle/features/catalog/presentation/search/widgets/catalog_filter_panel.dart';
+import 'package:shuffle/features/catalog/presentation/search/widgets/catalog_game_tile.dart';
+import 'package:shuffle/features/catalog/presentation/search/widgets/catalog_search_field.dart';
+
+/// Content of the catalog search: search field, filters, result list
+/// (Spec #3 § 5.6). Kept separate from the screen so the start page without
+/// sign-in (QUE-09, #29) can embed it.
+class CatalogSearchView extends ConsumerStatefulWidget {
+  const CatalogSearchView({
+    required this.initialQuery,
+    super.key,
+    this.onReportGame,
+    this.syncUrl = false,
+    this.autofocusSearch = kIsWeb,
+  });
+
+  /// Query the search starts with (from the URL).
+  final CatalogSearchQuery initialQuery;
+
+  /// Entry point to report a missing game from the empty state (KAT-04, #13).
+  /// `null` hides the action; #3 passes `null`.
+  final ValueChanged<String>? onReportGame;
+
+  /// Writes the search into the browser URL after each search (web only).
+  final bool syncUrl;
+
+  /// Focus the search field on open. Web only by default: on phones the
+  /// keyboard would cover the list.
+  final bool autofocusSearch;
+
+  @override
+  ConsumerState<CatalogSearchView> createState() => _CatalogSearchViewState();
+}
+
+/// Max width of the result column on large screens.
+const double _maxResultWidth = 720;
+const double _sidebarWidth = 320;
+
+/// Load the next page when less than about five tiles are left below.
+const double _autoLoadExtent = 500;
+
+/// Pause before announcing the hit count, so quick filter changes do not
+/// queue up announcements.
+const Duration _announceDelay = Duration(milliseconds: 600);
+
+class _CatalogSearchViewState extends ConsumerState<CatalogSearchView> {
+  final ScrollController _scroll = ScrollController();
+  final FocusNode _newTileFocus = FocusNode();
+  Timer? _announceTimer;
+  final List<ProviderSubscription<Object?>> _termSubscriptions = [];
+
+  /// Index of the first tile that came with "load more"; it takes focus.
+  int? _focusIndex;
+  bool _focusHandled = false;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (mounted) {
+        ref
+            .read(catalogSearchControllerProvider.notifier)
+            .init(widget.initialQuery);
+        _pruneUnknownTerms();
+      }
+    });
+  }
+
+  /// IDs from the URL that the vocabulary does not know are dropped once it is
+  /// loaded (the search then runs again, the URL follows). A load error
+  /// removes nothing.
+  void _pruneUnknownTerms() {
+    final filters = widget.initialQuery.filters;
+    if (filters.genreIds.isNotEmpty) {
+      _termSubscriptions.add(
+        ref.listenManual<AsyncValue<List<CatalogTerm>>>(catalogGenresProvider, (
+          AsyncValue<List<CatalogTerm>>? previous,
+          AsyncValue<List<CatalogTerm>> next,
+        ) {
+          final terms = next.value;
+          if (terms != null) {
+            _controller.retainKnownGenres({for (final t in terms) t.id});
+          }
+        }, fireImmediately: true),
+      );
+    }
+    if (filters.mechanicIds.isNotEmpty) {
+      _termSubscriptions.add(
+        ref.listenManual<AsyncValue<List<CatalogTerm>>>(
+          catalogMechanicsProvider,
+          (
+            AsyncValue<List<CatalogTerm>>? previous,
+            AsyncValue<List<CatalogTerm>> next,
+          ) {
+            final terms = next.value;
+            if (terms != null) {
+              _controller.retainKnownMechanics({for (final t in terms) t.id});
+            }
+          },
+          fireImmediately: true,
+        ),
+      );
+    }
+  }
+
+  @override
+  void dispose() {
+    _announceTimer?.cancel();
+    for (final subscription in _termSubscriptions) {
+      subscription.close();
+    }
+    _scroll.dispose();
+    _newTileFocus.dispose();
+    super.dispose();
+  }
+
+  CatalogSearchController get _controller =>
+      ref.read(catalogSearchControllerProvider.notifier);
+
+  void _onSearchCompleted() {
+    _focusIndex = null;
+    _focusHandled = false;
+    _announceTimer?.cancel();
+    _announceTimer = Timer(_announceDelay, _announce);
+    if (widget.syncUrl) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (!mounted) {
+          return;
+        }
+        final searched = ref
+            .read(catalogSearchControllerProvider)
+            .searchedQuery;
+        ref
+            .read(urlReplacerProvider)
+            .replace(context, catalogLocation(AppRoutes.catalog, searched));
+      });
+    }
+  }
+
+  void _announce() {
+    if (!mounted) {
+      return;
+    }
+    final state = ref.read(catalogSearchControllerProvider);
+    if (state.refreshing ||
+        (state.status != CatalogSearchStatus.data &&
+            state.status != CatalogSearchStatus.empty)) {
+      return;
+    }
+    unawaited(
+      SemanticsService.sendAnnouncement(
+        View.of(context),
+        context.l10n.catalogSearchAnnouncement(state.totalCount),
+        Directionality.of(context),
+      ),
+    );
+  }
+
+  void _loadMoreByUser() {
+    final state = ref.read(catalogSearchControllerProvider);
+    _focusIndex = state.items.length;
+    _focusHandled = false;
+    if (state.loadMoreFailure != null) {
+      unawaited(_controller.retry());
+    } else {
+      unawaited(_controller.loadMore());
+    }
+  }
+
+  /// Auto-loading when the end of the list is near (also when the first page
+  /// does not fill the viewport, so no scroll event can ever come).
+  void _checkAutoLoad() {
+    if (!mounted || !_scroll.hasClients) {
+      return;
+    }
+    final state = ref.read(catalogSearchControllerProvider);
+    if (state.status != CatalogSearchStatus.data ||
+        !state.hasMore ||
+        state.loadingMore ||
+        state.refreshing ||
+        state.loadMoreFailure != null) {
+      return;
+    }
+    if (_scroll.position.extentAfter < _autoLoadExtent) {
+      unawaited(_controller.loadMore());
+    }
+  }
+
+  void _scheduleAutoLoadCheck() {
+    WidgetsBinding.instance.addPostFrameCallback((_) => _checkAutoLoad());
+  }
+
+  void _scheduleFocus(CatalogSearchState state) {
+    final index = _focusIndex;
+    if (index == null || _focusHandled || state.items.length <= index) {
+      return;
+    }
+    _focusHandled = true;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted || !_newTileFocus.canRequestFocus) {
+        return;
+      }
+      _newTileFocus.requestFocus();
+      final focusContext = _newTileFocus.context;
+      if (focusContext != null) {
+        unawaited(Scrollable.ensureVisible(focusContext));
+      }
+    });
+  }
+
+  Future<void> _openFilters() {
+    final l10n = context.l10n;
+    return showModalBottomSheet<void>(
+      context: context,
+      isScrollControlled: true,
+      useSafeArea: true,
+      showDragHandle: true,
+      builder: (sheetContext) => Consumer(
+        builder: (context, ref, _) {
+          final filters = ref.watch(
+            catalogSearchControllerProvider.select((s) => s.query.filters),
+          );
+          return Column(
+            key: const Key('catalog_filter_sheet'),
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Padding(
+                padding: const EdgeInsets.symmetric(horizontal: AppSpacing.lg),
+                child: Row(
+                  children: [
+                    Expanded(
+                      child: Semantics(
+                        header: true,
+                        child: Text(
+                          l10n.catalogSearchFilterTitle,
+                          style: Theme.of(context).textTheme.titleLarge,
+                        ),
+                      ),
+                    ),
+                    TextButton(
+                      key: const Key('catalog_filter_done'),
+                      onPressed: () => Navigator.of(sheetContext).pop(),
+                      child: Text(l10n.catalogSearchFilterDone),
+                    ),
+                  ],
+                ),
+              ),
+              Flexible(
+                child: SingleChildScrollView(
+                  padding: const EdgeInsets.all(AppSpacing.lg),
+                  child: CatalogFilterPanel(
+                    filters: filters,
+                    onChanged: _controller.setFilters,
+                  ),
+                ),
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    ref.listen(
+      catalogSearchControllerProvider.select((s) => s.searchGeneration),
+      (previous, next) => _onSearchCompleted(),
+    );
+    final state = ref.watch(catalogSearchControllerProvider);
+    _scheduleFocus(state);
+
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        // Also on a size change (without a state change): a larger window
+        // may show the whole list, so no scroll event would ever come.
+        if (state.status == CatalogSearchStatus.data) {
+          _scheduleAutoLoadCheck();
+        }
+        final width = constraints.maxWidth;
+        final expanded = AppWidthClass.of(width) == AppWidthClass.expanded;
+        final padding = AppSpacing.pagePadding(width);
+        final main = Align(
+          alignment: Alignment.topCenter,
+          child: ConstrainedBox(
+            constraints: const BoxConstraints(maxWidth: _maxResultWidth),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                FocusTraversalOrder(
+                  order: const NumericFocusOrder(1),
+                  child: Padding(
+                    padding: EdgeInsets.fromLTRB(
+                      padding.left,
+                      padding.top,
+                      padding.right,
+                      AppSpacing.sm,
+                    ),
+                    child: _buildHeader(state, showFilterButton: !expanded),
+                  ),
+                ),
+                Expanded(
+                  child: FocusTraversalOrder(
+                    order: const NumericFocusOrder(3),
+                    child: _buildResults(state, padding),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        );
+        // Tab order (Spec #3 § 6): search field, filters, list. With the side
+        // bar left of the field the visual order alone would be wrong.
+        return FocusTraversalGroup(
+          policy: OrderedTraversalPolicy(),
+          child: expanded
+              ? Row(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    FocusTraversalOrder(
+                      order: const NumericFocusOrder(2),
+                      child: SizedBox(
+                        width: _sidebarWidth,
+                        child: SingleChildScrollView(
+                          key: const Key('catalog_filter_sidebar'),
+                          padding: EdgeInsets.all(padding.left),
+                          child: _buildSidebar(state),
+                        ),
+                      ),
+                    ),
+                    const VerticalDivider(width: 1),
+                    Expanded(child: main),
+                  ],
+                )
+              : main,
+        );
+      },
+    );
+  }
+
+  Widget _buildSidebar(CatalogSearchState state) {
+    final l10n = context.l10n;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Semantics(
+          header: true,
+          child: Text(
+            l10n.catalogSearchFilterTitle,
+            style: Theme.of(context).textTheme.titleLarge,
+          ),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        CatalogFilterPanel(
+          filters: state.query.filters,
+          onChanged: _controller.setFilters,
+        ),
+      ],
+    );
+  }
+
+  Widget _buildHeader(
+    CatalogSearchState state, {
+    required bool showFilterButton,
+  }) {
+    final l10n = context.l10n;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        CatalogSearchField(
+          initialText: widget.initialQuery.text,
+          autofocus: widget.autofocusSearch,
+          onChanged: _controller.setText,
+          onSubmitted: _controller.submitText,
+        ),
+        if (showFilterButton) ...[
+          const SizedBox(height: AppSpacing.sm),
+          Align(
+            alignment: AlignmentDirectional.centerStart,
+            child: OutlinedButton.icon(
+              key: const Key('catalog_filter_button'),
+              onPressed: _openFilters,
+              icon: const Icon(Icons.tune),
+              label: Text(
+                l10n.catalogSearchFilterButton(state.query.activeFilterCount),
+              ),
+            ),
+          ),
+        ],
+      ],
+    );
+  }
+
+  Widget _buildResults(CatalogSearchState state, EdgeInsets padding) {
+    final l10n = context.l10n;
+    switch (state.status) {
+      case CatalogSearchStatus.loading:
+        return Center(
+          child: Semantics(
+            label: l10n.catalogSearchLoading,
+            liveRegion: true,
+            child: const CircularProgressIndicator(key: Key('catalog_loading')),
+          ),
+        );
+      case CatalogSearchStatus.error:
+        final failure = state.failure;
+        final offline = failure is CatalogNetworkFailure;
+        // Rejected input does not get better by repeating it: no retry.
+        final invalid = failure is CatalogInvalidInputFailure;
+        return AppStateMessage(
+          key: const Key('catalog_error'),
+          icon: offline ? Icons.wifi_off : Icons.error_outline,
+          title: offline
+              ? l10n.catalogSearchErrorOffline
+              : invalid
+              ? l10n.catalogSearchErrorInvalid
+              : l10n.catalogSearchErrorGeneric,
+          actions: [
+            if (!invalid)
+              AppStateAction(
+                key: const Key('catalog_error_retry'),
+                label: l10n.catalogSearchRetry,
+                onPressed: () => unawaited(_controller.retry()),
+              ),
+          ],
+        );
+      case CatalogSearchStatus.empty:
+        return CatalogEmptyState(
+          query: state.searchedQuery,
+          onResetFilters: _controller.clearFilters,
+          onReportGame: widget.onReportGame,
+        );
+      case CatalogSearchStatus.data:
+        return _buildList(state, padding);
+    }
+  }
+
+  Widget _buildList(CatalogSearchState state, EdgeInsets padding) {
+    final l10n = context.l10n;
+    final items = state.items;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        if (state.refreshing)
+          Semantics(
+            label: l10n.catalogSearchLoading,
+            child: const LinearProgressIndicator(
+              key: Key('catalog_refreshing'),
+              minHeight: 2,
+            ),
+          ),
+        Padding(
+          padding: EdgeInsets.symmetric(horizontal: padding.left),
+          child: Align(
+            alignment: AlignmentDirectional.centerStart,
+            child: Text(
+              l10n.catalogSearchResultCount(state.totalCount),
+              key: const Key('catalog_result_count'),
+              style: Theme.of(context).textTheme.labelLarge,
+            ),
+          ),
+        ),
+        Expanded(
+          child: NotificationListener<ScrollNotification>(
+            onNotification: (notification) {
+              _checkAutoLoad();
+              return false;
+            },
+            child: ListView.builder(
+              key: const Key('catalog_result_list'),
+              controller: _scroll,
+              padding: EdgeInsets.symmetric(
+                horizontal: padding.left,
+                vertical: AppSpacing.sm,
+              ),
+              itemCount: items.length + 1,
+              itemBuilder: (context, index) {
+                if (index == items.length) {
+                  return AppListFooter(
+                    isLoading: state.loadingMore,
+                    hasMore: state.hasMore,
+                    errorMessage: state.loadMoreFailure != null
+                        ? l10n.catalogSearchLoadMoreError
+                        : null,
+                    loadingLabel: l10n.catalogSearchLoading,
+                    loadMoreLabel: l10n.catalogSearchLoadMore,
+                    retryLabel: l10n.catalogSearchRetry,
+                    onLoadMore: _loadMoreByUser,
+                    onRetry: _loadMoreByUser,
+                  );
+                }
+                return CatalogGameTile(
+                  key: ValueKey(items[index].id),
+                  game: items[index],
+                  focusNode: index == _focusIndex ? _newTileFocus : null,
+                );
+              },
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}

app/lib/features/catalog/presentation/search/widgets/catalog_empty_state.dart

@@ -0,0 +1,66 @@
+import 'package:flutter/material.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/widgets/app_state_message.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+
+/// Empty list of the catalog search (Spec #3 § 5.6, KAT-01 criteria 6 and 8).
+///
+/// [query] is the query the (empty) result belongs to. With a search text the
+/// widget shows the hint and, if [onReportGame] is set, the entry point to
+/// report a missing game (KAT-04 / #13 sets it; #3 passes `null`).
+class CatalogEmptyState extends StatelessWidget {
+  const CatalogEmptyState({
+    required this.query,
+    required this.onResetFilters,
+    super.key,
+    this.onReportGame,
+  });
+
+  final CatalogSearchQuery query;
+  final VoidCallback onResetFilters;
+
+  /// Receives the search text. `null` hides the action.
+  final ValueChanged<String>? onReportGame;
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    final reset = AppStateAction(
+      key: const Key('catalog_empty_reset'),
+      label: l10n.catalogSearchFilterReset,
+      onPressed: onResetFilters,
+    );
+    final report = onReportGame;
+
+    if (query.hasText) {
+      return AppStateMessage(
+        key: const Key('catalog_empty_query'),
+        icon: Icons.search_off,
+        title: l10n.catalogSearchEmptyForQuery(query.text),
+        message: l10n.catalogSearchEmptyForQueryHint,
+        actions: [
+          if (query.hasFilters) reset,
+          if (report != null)
+            AppStateAction(
+              key: const Key('catalog_empty_report'),
+              label: l10n.catalogSearchReportGame,
+              onPressed: () => report(query.text),
+            ),
+        ],
+      );
+    }
+    if (query.hasFilters) {
+      return AppStateMessage(
+        key: const Key('catalog_empty_filters'),
+        icon: Icons.filter_alt_off_outlined,
+        title: l10n.catalogSearchEmptyForFilters,
+        actions: [reset],
+      );
+    }
+    return AppStateMessage(
+      key: const Key('catalog_empty_catalog'),
+      icon: Icons.inventory_2_outlined,
+      title: l10n.catalogSearchEmptyCatalog,
+    );
+  }
+}

app/lib/features/catalog/presentation/search/widgets/catalog_filter_panel.dart

@@ -0,0 +1,270 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/theme/app_spacing.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+import 'package:shuffle/features/catalog/presentation/providers/catalog_providers.dart';
+
+/// Filter area (Spec #3 § 5.6): player count, play time, age, genres and
+/// mechanics, reset. Used in the bottom sheet (compact/medium) and the side
+/// bar (expanded). Changes apply immediately through [onChanged].
+class CatalogFilterPanel extends ConsumerWidget {
+  const CatalogFilterPanel({
+    required this.filters,
+    required this.onChanged,
+    super.key,
+  });
+
+  final CatalogFilters filters;
+  final ValueChanged<CatalogFilters> onChanged;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final l10n = context.l10n;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        _SingleChoice(
+          fieldKey: const Key('catalog_filter_players'),
+          label: l10n.catalogSearchFilterPlayers,
+          anyLabel: l10n.catalogSearchFilterAny,
+          value: filters.players,
+          options: [
+            for (
+              var n = CatalogSearchLimits.minPlayers;
+              n <= CatalogSearchLimits.maxPlayers;
+              n++
+            )
+              n,
+          ],
+          optionLabel: l10n.catalogSearchPlayersCount,
+          onChanged: (v) => onChanged(filters.copyWith(players: v)),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        _SingleChoice(
+          fieldKey: const Key('catalog_filter_duration'),
+          label: l10n.catalogSearchFilterDuration,
+          anyLabel: l10n.catalogSearchFilterAny,
+          value: filters.maxMinutes,
+          options: CatalogSearchLimits.maxMinutesSteps,
+          optionLabel: l10n.catalogSearchFilterDurationValue,
+          onChanged: (v) => onChanged(filters.copyWith(maxMinutes: v)),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        _SingleChoice(
+          fieldKey: const Key('catalog_filter_age'),
+          label: l10n.catalogSearchFilterAge,
+          anyLabel: l10n.catalogSearchFilterAny,
+          value: filters.minAgeSuitable,
+          options: CatalogSearchLimits.ageSteps,
+          optionLabel: l10n.catalogSearchFilterAgeValue,
+          onChanged: (v) => onChanged(filters.copyWith(minAgeSuitable: v)),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        _TermChoice(
+          sectionKey: const Key('catalog_filter_genres'),
+          label: l10n.catalogSearchFilterGenres,
+          terms: ref.watch(catalogGenresProvider),
+          onRetry: () => ref.invalidate(catalogGenresProvider),
+          selected: filters.genreIds,
+          onChanged: (ids) => onChanged(filters.copyWith(genreIds: ids)),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        _TermChoice(
+          sectionKey: const Key('catalog_filter_mechanics'),
+          label: l10n.catalogSearchFilterMechanics,
+          terms: ref.watch(catalogMechanicsProvider),
+          onRetry: () => ref.invalidate(catalogMechanicsProvider),
+          selected: filters.mechanicIds,
+          onChanged: (ids) => onChanged(filters.copyWith(mechanicIds: ids)),
+        ),
+        const SizedBox(height: AppSpacing.lg),
+        Align(
+          alignment: AlignmentDirectional.centerStart,
+          child: TextButton(
+            key: const Key('catalog_filter_reset'),
+            onPressed: filters.isEmpty
+                ? null
+                : () => onChanged(const CatalogFilters()),
+            child: Text(l10n.catalogSearchFilterReset),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+/// Single selection with "any" (drop-down, 48 dp, labeled).
+class _SingleChoice extends StatelessWidget {
+  const _SingleChoice({
+    required this.fieldKey,
+    required this.label,
+    required this.anyLabel,
+    required this.value,
+    required this.options,
+    required this.optionLabel,
+    required this.onChanged,
+  });
+
+  final Key fieldKey;
+  final String label;
+  final String anyLabel;
+  final int? value;
+  final List<int> options;
+  final String Function(int) optionLabel;
+  final ValueChanged<int?> onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    // A controlled drop-down (no form field that keeps its own value), so a
+    // selection does not rebuild the field and keyboard focus stays on it.
+    return KeyedSubtree(
+      key: fieldKey,
+      child: InputDecorator(
+        // "Any" is a value too, so the label always floats.
+        isEmpty: false,
+        decoration: InputDecoration(labelText: label),
+        child: DropdownButtonHideUnderline(
+          child: DropdownButton<int?>(
+            value: value,
+            isExpanded: true,
+            items: [
+              DropdownMenuItem<int?>(child: Text(anyLabel)),
+              for (final option in options)
+                DropdownMenuItem<int?>(
+                  value: option,
+                  child: Text(optionLabel(option)),
+                ),
+            ],
+            onChanged: onChanged,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+/// Multi selection as filter chips, sorted by the localized name.
+class _TermChoice extends StatelessWidget {
+  const _TermChoice({
+    required this.sectionKey,
+    required this.label,
+    required this.terms,
+    required this.onRetry,
+    required this.selected,
+    required this.onChanged,
+  });
+
+  final Key sectionKey;
+  final String label;
+  final AsyncValue<List<CatalogTerm>> terms;
+  final VoidCallback onRetry;
+  final Set<String> selected;
+  final ValueChanged<Set<String>> onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    final theme = Theme.of(context);
+    final language = Localizations.localeOf(context).languageCode;
+
+    final Widget content = terms.when(
+      data: (list) {
+        final sorted = [...list]
+          ..sort(
+            (a, b) =>
+                _sortKey(a.localizedName(language))
+                    .compareTo(_sortKey(b.localizedName(language))),
+          );
+        final full = selected.length >= CatalogSearchLimits.maxTerms;
+        return Wrap(
+          spacing: AppSpacing.sm,
+          runSpacing: AppSpacing.xs,
+          children: [
+            for (final term in sorted)
+              FilterChip(
+                key: Key('catalog_term_${term.id}'),
+                label: Text(term.localizedName(language)),
+                selected: selected.contains(term.id),
+                onSelected: !selected.contains(term.id) && full
+                    ? null
+                    : (on) => onChanged(
+                        on
+                            ? {...selected, term.id}
+                            : ({...selected}..remove(term.id)),
+                      ),
+              ),
+          ],
+        );
+      },
+      loading: () => const Padding(
+        padding: EdgeInsets.all(AppSpacing.sm),
+        child: Center(child: CircularProgressIndicator()),
+      ),
+      error: (error, stack) => Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Semantics(
+            liveRegion: true,
+            child: Text(
+              l10n.catalogSearchTermsError,
+              style: theme.textTheme.bodyMedium?.copyWith(
+                color: theme.colorScheme.error,
+              ),
+            ),
+          ),
+          TextButton(
+            key: const Key('catalog_terms_retry'),
+            onPressed: onRetry,
+            child: Text(l10n.catalogSearchRetry),
+          ),
+        ],
+      ),
+    );
+
+    return Column(
+      key: sectionKey,
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Semantics(
+          header: true,
+          child: Text(label, style: theme.textTheme.titleSmall),
+        ),
+        const SizedBox(height: AppSpacing.sm),
+        content,
+      ],
+    );
+  }
+}
+
+/// Sort key that puts umlauts and accents next to their base letters.
+String _sortKey(String name) {
+  const map = {
+    'ä': 'a',
+    'ö': 'o',
+    'ü': 'u',
+    'ß': 'ss',
+    'é': 'e',
+    'è': 'e',
+    'ê': 'e',
+    'á': 'a',
+    'à': 'a',
+    'â': 'a',
+    'í': 'i',
+    'ó': 'o',
+    'ô': 'o',
+    'ú': 'u',
+    'ç': 'c',
+    'ñ': 'n',
+    'æ': 'ae',
+    'œ': 'oe',
+  };
+  final buffer = StringBuffer();
+  for (final rune in name.toLowerCase().runes) {
+    final char = String.fromCharCode(rune);
+    buffer.write(map[char] ?? char);
+  }
+  return buffer.toString();
+}

app/lib/features/catalog/presentation/search/widgets/catalog_game_tile.dart

@@ -0,0 +1,179 @@
+import 'package:flutter/material.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/theme/app_spacing.dart';
+import 'package:shuffle/core/widgets/game_cover.dart';
+import 'package:shuffle/features/catalog/domain/catalog_game_summary.dart';
+
+/// Result tile of the catalog search (Spec #3 § 5.6).
+///
+/// Shows a [GameCover] placeholder (no image URL in #3), title, year,
+/// publishers and short facts; missing facts are left out. [onTap] is `null`
+/// in #3: the tile is then not a button (no dead link) but stays a keyboard
+/// stop with a visible focus ring, so keyboard users can walk the list (which
+/// scrolls it and loads more) and focus can move to the first newly loaded
+/// tile ([focusNode]).
+class CatalogGameTile extends StatefulWidget {
+  const CatalogGameTile({
+    required this.game,
+    super.key,
+    this.onTap,
+    this.focusNode,
+  });
+
+  final CatalogGameSummary game;
+  final VoidCallback? onTap;
+  final FocusNode? focusNode;
+
+  /// Facts line, e.g. "2–4 Spieler · 30–60 Min. · ab 10" (missing parts are
+  /// left out).
+  static List<String> facts(AppLocalizations l10n, CatalogGameSummary game) {
+    String? players() {
+      final min = game.minPlayers;
+      final max = game.maxPlayers;
+      if (min != null && max != null && min != max) {
+        return l10n.catalogSearchPlayersRange(min, max);
+      }
+      final single = min ?? max;
+      return single == null ? null : l10n.catalogSearchPlayersCount(single);
+    }
+
+    String? minutes() {
+      final min = game.minMinutes;
+      final max = game.maxMinutes;
+      if (min != null && max != null && min != max) {
+        return l10n.catalogSearchMinutesRange(min, max);
+      }
+      final single = max ?? min;
+      return single == null ? null : l10n.catalogSearchMinutesSingle(single);
+    }
+
+    final age = game.minAge;
+    return [
+      ?players(),
+      ?minutes(),
+      if (age != null) l10n.catalogSearchMinAge(age),
+    ];
+  }
+
+  /// Up to two publishers, then "+n".
+  static String? publishers(AppLocalizations l10n, CatalogGameSummary game) {
+    final names = game.publisherNames;
+    if (names.isEmpty) {
+      return null;
+    }
+    final shown = names.take(2).join(', ');
+    final more = names.length - 2;
+    return more > 0 ? l10n.catalogSearchPublishersMore(shown, more) : shown;
+  }
+
+  @override
+  State<CatalogGameTile> createState() => _CatalogGameTileState();
+}
+
+class _CatalogGameTileState extends State<CatalogGameTile> {
+  bool _focused = false;
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    final theme = Theme.of(context);
+    final scheme = theme.colorScheme;
+    final game = widget.game;
+    final facts = CatalogGameTile.facts(l10n, game);
+    final publishers = CatalogGameTile.publishers(l10n, game);
+    final subtitle = [
+      if (game.year != null) '${game.year}',
+      ?publishers,
+    ].join(' · ');
+    final alt = game.matchedAltTitle;
+
+    final label = [
+      game.title,
+      if (subtitle.isNotEmpty) subtitle,
+      if (facts.isNotEmpty) facts.join(', '),
+      if (alt != null) l10n.catalogSearchAlsoKnownAs(alt),
+    ].join(', ');
+
+    final body = Padding(
+      padding: const EdgeInsets.all(AppSpacing.md),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          GameCover(title: game.title, titleVisibleNearby: true),
+          const SizedBox(width: AppSpacing.md),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  game.title,
+                  maxLines: 2,
+                  overflow: TextOverflow.ellipsis,
+                  style: theme.textTheme.titleMedium,
+                ),
+                if (alt != null)
+                  Text(
+                    l10n.catalogSearchAlsoKnownAs(alt),
+                    maxLines: 2,
+                    overflow: TextOverflow.ellipsis,
+                    style: theme.textTheme.bodyMedium?.copyWith(
+                      fontStyle: FontStyle.italic,
+                      color: scheme.onSurfaceVariant,
+                    ),
+                  ),
+                if (subtitle.isNotEmpty)
+                  Text(
+                    subtitle,
+                    maxLines: 2,
+                    overflow: TextOverflow.ellipsis,
+                    style: theme.textTheme.bodyMedium?.copyWith(
+                      color: scheme.onSurfaceVariant,
+                    ),
+                  ),
+                if (facts.isNotEmpty)
+                  Padding(
+                    padding: const EdgeInsets.only(top: AppSpacing.xs),
+                    child: Text(
+                      facts.join(' · '),
+                      style: theme.textTheme.bodyMedium,
+                    ),
+                  ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+
+    final onTap = widget.onTap;
+    return Focus(
+      focusNode: widget.focusNode,
+      onFocusChange: (focused) => setState(() => _focused = focused),
+      child: Semantics(
+        container: true,
+        button: onTap != null,
+        label: label,
+        onTap: onTap,
+        child: ExcludeSemantics(
+          child: Card(
+            key: Key('catalog_tile_${game.id}'),
+            margin: const EdgeInsets.symmetric(vertical: AppSpacing.xs),
+            shape: RoundedRectangleBorder(
+              borderRadius: AppRadius.mdAll,
+              side: _focused
+                  ? BorderSide(color: scheme.primary, width: 3)
+                  : BorderSide(color: scheme.outlineVariant),
+            ),
+            child: onTap == null
+                ? body
+                : InkWell(
+                    borderRadius: AppRadius.mdAll,
+                    onTap: onTap,
+                    child: body,
+                  ),
+          ),
+        ),
+      ),
+    );
+  }
+}

app/lib/features/catalog/presentation/search/widgets/catalog_search_field.dart

@@ -0,0 +1,83 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/widgets/app_text_field.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+
+/// Search field of the catalog search (Spec #3 § 5.6): visible label and
+/// hint, search keyboard action, hard limit of 100 characters without
+/// counter, clear button (48 dp).
+class CatalogSearchField extends StatefulWidget {
+  const CatalogSearchField({
+    required this.initialText,
+    required this.onChanged,
+    required this.onSubmitted,
+    super.key,
+    this.autofocus = false,
+  });
+
+  final String initialText;
+  final bool autofocus;
+
+  /// Called on every edit.
+  final ValueChanged<String> onChanged;
+
+  /// Called on Enter and when the text is cleared: search without debounce.
+  final ValueChanged<String> onSubmitted;
+
+  @override
+  State<CatalogSearchField> createState() => _CatalogSearchFieldState();
+}
+
+class _CatalogSearchFieldState extends State<CatalogSearchField> {
+  late final TextEditingController _controller = TextEditingController(
+    text: widget.initialText,
+  );
+  final FocusNode _focusNode = FocusNode();
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    _focusNode.dispose();
+    super.dispose();
+  }
+
+  void _clear() {
+    _controller.clear();
+    widget.onSubmitted('');
+    _focusNode.requestFocus();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    return AppTextField(
+      key: const Key('catalog_search_field'),
+      label: l10n.catalogSearchTitle,
+      helperText: l10n.catalogSearchFieldHint,
+      controller: _controller,
+      focusNode: _focusNode,
+      autofocus: widget.autofocus,
+      textInputAction: TextInputAction.search,
+      keyboardType: TextInputType.text,
+      autocorrect: false,
+      enableSuggestions: false,
+      inputFormatters: [
+        LengthLimitingTextInputFormatter(CatalogSearchLimits.maxTextLength),
+      ],
+      onChanged: widget.onChanged,
+      onSubmitted: widget.onSubmitted,
+      suffixIcon: ValueListenableBuilder<TextEditingValue>(
+        valueListenable: _controller,
+        builder: (context, value, _) => value.text.isEmpty
+            ? const SizedBox.shrink()
+            : IconButton(
+                key: const Key('catalog_search_clear'),
+                tooltip: l10n.catalogSearchClear,
+                icon: const Icon(Icons.close),
+                onPressed: _clear,
+              ),
+      ),
+    );
+  }
+}

app/lib/features/catalog/presentation/widgets/catalog_search_entry_button.dart

@@ -0,0 +1,21 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:shuffle/core/l10n/l10n.dart';
+import 'package:shuffle/core/routing/app_routes.dart';
+
+/// Entry from the start page to the catalog search (Spec #3 § 5.5). The start
+/// page without sign-in (QUE-09, #29) replaces this with the search itself.
+class CatalogSearchEntryButton extends StatelessWidget {
+  const CatalogSearchEntryButton({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final label = context.l10n.catalogSearchTitle;
+    return FilledButton.icon(
+      key: const Key('home_catalog_search_button'),
+      onPressed: () => context.go(AppRoutes.catalog),
+      icon: const Icon(Icons.search),
+      label: Text(label),
+    );
+  }
+}

app/lib/features/home/presentation/home_screen.dart

@@ -4,6 +4,7 @@ import 'package:shuffle/core/l10n/l10n.dart';
 import 'package:shuffle/core/theme/app_spacing.dart';
 import 'package:shuffle/features/auth/presentation/providers/sign_in_prompt_provider.dart';
 import 'package:shuffle/features/auth/presentation/widgets/sign_in_prompt.dart';
+import 'package:shuffle/features/catalog/presentation/widgets/catalog_search_entry_button.dart';
 
 /// Placeholder home screen. To be replaced by the catalog search / QUE-09.
 ///
@@ -40,6 +41,8 @@ class HomeScreen extends ConsumerWidget {
                       const SizedBox(height: AppSpacing.xl),
                       const SignInPrompt(),
                     ],
+                    const SizedBox(height: AppSpacing.xl),
+                    const CatalogSearchEntryButton(),
                   ],
                 ),
               ),

app/lib/l10n/app_de.arb

@@ -83,5 +83,42 @@
   "authResetCancel": "Abbrechen",
   "authPasswordChanged": "Passwort geändert. Andere Geräte werden abgemeldet; das kann bis zu einer Stunde dauern.",
   "gameCoverPlaceholderLabel": "Kein Cover für {title}",
-  "gameCoverLabel": "Cover von {title}"
+  "gameCoverLabel": "Cover von {title}",
+  "catalogSearchTitle": "Spiele suchen",
+  "catalogSearchFieldHint": "Titel oder Verlag",
+  "catalogSearchClear": "Suchbegriff löschen",
+  "catalogSearchFilterButton": "{count, plural, =0{Filter} other{Filter ({count})}}",
+  "catalogSearchFilterTitle": "Filter",
+  "catalogSearchFilterDone": "Fertig",
+  "catalogSearchFilterReset": "Filter zurücksetzen",
+  "catalogSearchFilterPlayers": "Spielerzahl",
+  "catalogSearchFilterAny": "Beliebig",
+  "catalogSearchFilterDuration": "Spieldauer",
+  "catalogSearchFilterDurationValue": "Bis {minutes} Min.",
+  "catalogSearchFilterAge": "Alter",
+  "catalogSearchFilterAgeValue": "Ab {age} Jahren geeignet",
+  "catalogSearchFilterGenres": "Genre",
+  "catalogSearchFilterMechanics": "Mechanik",
+  "catalogSearchTermsError": "Die Auswahl konnte nicht geladen werden.",
+  "catalogSearchRetry": "Erneut versuchen",
+  "catalogSearchResultCount": "{count, plural, =0{Keine Spiele} =1{1 Spiel} other{{count} Spiele}}",
+  "catalogSearchAnnouncement": "{count, plural, =0{Keine Spiele gefunden} =1{1 Spiel gefunden} other{{count} Spiele gefunden}}",
+  "catalogSearchAlsoKnownAs": "auch: {title}",
+  "catalogSearchPlayersCount": "{count, plural, =1{1 Spieler} other{{count} Spieler}}",
+  "catalogSearchPlayersRange": "{min}–{max} Spieler",
+  "catalogSearchMinutesSingle": "{minutes} Min.",
+  "catalogSearchMinutesRange": "{min}–{max} Min.",
+  "catalogSearchMinAge": "ab {age}",
+  "catalogSearchPublishersMore": "{names} +{more}",
+  "catalogSearchLoadMore": "Weitere laden",
+  "catalogSearchLoading": "Treffer werden geladen",
+  "catalogSearchLoadMoreError": "Weitere Treffer konnten nicht geladen werden.",
+  "catalogSearchEmptyForQuery": "Keine Spiele zu „{query}“ gefunden.",
+  "catalogSearchEmptyForQueryHint": "Prüfe die Schreibweise oder entferne Filter.",
+  "catalogSearchEmptyForFilters": "Keine Spiele passen zu deinen Filtern.",
+  "catalogSearchEmptyCatalog": "Der Katalog ist noch leer.",
+  "catalogSearchReportGame": "Fehlendes Spiel melden",
+  "catalogSearchErrorOffline": "Keine Verbindung. Für die Suche brauchst du Internet.",
+  "catalogSearchErrorGeneric": "Die Suche ist gerade nicht möglich.",
+  "catalogSearchErrorInvalid": "Diese Suche wird nicht unterstützt. Ändere den Suchbegriff oder die Filter."
 }

app/lib/l10n/app_en.arb

@@ -137,5 +137,79 @@
   "@gameCoverLabel": {
     "description": "Semantics label of a game cover image",
     "placeholders": {"title": {"type": "String"}}
-  }
+  },
+  "catalogSearchTitle": "Search games",
+  "@catalogSearchTitle": {"description": "Title of the catalog search screen and label of the search field/entry button"},
+  "catalogSearchFieldHint": "Title or publisher",
+  "@catalogSearchFieldHint": {"description": "Hint text of the search field"},
+  "catalogSearchClear": "Clear search",
+  "@catalogSearchClear": {"description": "Tooltip/label of the clear button of the search field"},
+  "catalogSearchFilterButton": "{count, plural, =0{Filters} other{Filters ({count})}}",
+  "@catalogSearchFilterButton": {"description": "Button that opens the filters, with the number of active filters", "placeholders": {"count": {"type": "int"}}},
+  "catalogSearchFilterTitle": "Filters",
+  "@catalogSearchFilterTitle": {"description": "Title of the filter area"},
+  "catalogSearchFilterDone": "Done",
+  "@catalogSearchFilterDone": {"description": "Closes the filter sheet"},
+  "catalogSearchFilterReset": "Reset filters",
+  "@catalogSearchFilterReset": {"description": "Removes all filters"},
+  "catalogSearchFilterPlayers": "Number of players",
+  "@catalogSearchFilterPlayers": {"description": "Filter label"},
+  "catalogSearchFilterAny": "Any",
+  "@catalogSearchFilterAny": {"description": "Filter value without restriction"},
+  "catalogSearchFilterDuration": "Play time",
+  "@catalogSearchFilterDuration": {"description": "Filter label"},
+  "catalogSearchFilterDurationValue": "Up to {minutes} min",
+  "@catalogSearchFilterDurationValue": {"description": "Filter value: games lasting at most this many minutes", "placeholders": {"minutes": {"type": "int"}}},
+  "catalogSearchFilterAge": "Age",
+  "@catalogSearchFilterAge": {"description": "Filter label"},
+  "catalogSearchFilterAgeValue": "Suitable from age {age}",
+  "@catalogSearchFilterAgeValue": {"description": "Filter value: games suitable for players of this age", "placeholders": {"age": {"type": "int"}}},
+  "catalogSearchFilterGenres": "Genre",
+  "@catalogSearchFilterGenres": {"description": "Filter label"},
+  "catalogSearchFilterMechanics": "Mechanic",
+  "@catalogSearchFilterMechanics": {"description": "Filter label"},
+  "catalogSearchTermsError": "The options could not be loaded.",
+  "@catalogSearchTermsError": {"description": "Error in the genre/mechanic filter"},
+  "catalogSearchRetry": "Try again",
+  "@catalogSearchRetry": {"description": "Retry button"},
+  "catalogSearchResultCount": "{count, plural, =0{No games} =1{1 game} other{{count} games}}",
+  "@catalogSearchResultCount": {"description": "Number of hits above the list", "placeholders": {"count": {"type": "int", "format": "decimalPattern"}}},
+  "catalogSearchAnnouncement": "{count, plural, =0{No games found} =1{1 game found} other{{count} games found}}",
+  "@catalogSearchAnnouncement": {"description": "Screen reader announcement after a finished search", "placeholders": {"count": {"type": "int", "format": "decimalPattern"}}},
+  "catalogSearchAlsoKnownAs": "also: {title}",
+  "@catalogSearchAlsoKnownAs": {"description": "Alternative title that matched", "placeholders": {"title": {"type": "String"}}},
+  "catalogSearchPlayersCount": "{count, plural, =1{1 player} other{{count} players}}",
+  "@catalogSearchPlayersCount": {"description": "Number of players of a game", "placeholders": {"count": {"type": "int"}}},
+  "catalogSearchPlayersRange": "{min}–{max} players",
+  "@catalogSearchPlayersRange": {"description": "Player range of a game", "placeholders": {"min": {"type": "int"}, "max": {"type": "int"}}},
+  "catalogSearchMinutesSingle": "{minutes} min",
+  "@catalogSearchMinutesSingle": {"description": "Play time of a game", "placeholders": {"minutes": {"type": "int"}}},
+  "catalogSearchMinutesRange": "{min}–{max} min",
+  "@catalogSearchMinutesRange": {"description": "Play time range of a game", "placeholders": {"min": {"type": "int"}, "max": {"type": "int"}}},
+  "catalogSearchMinAge": "ages {age}+",
+  "@catalogSearchMinAge": {"description": "Minimum age of a game", "placeholders": {"age": {"type": "int"}}},
+  "catalogSearchPublishersMore": "{names} +{more}",
+  "@catalogSearchPublishersMore": {"description": "Publishers of a game, more than shown", "placeholders": {"names": {"type": "String"}, "more": {"type": "int"}}},
+  "catalogSearchLoadMore": "Load more",
+  "@catalogSearchLoadMore": {"description": "Button at the end of the list"},
+  "catalogSearchLoading": "Loading games",
+  "@catalogSearchLoading": {"description": "Spoken label of the loading indicator"},
+  "catalogSearchLoadMoreError": "More games could not be loaded.",
+  "@catalogSearchLoadMoreError": {"description": "Error when loading the next page"},
+  "catalogSearchEmptyForQuery": "No games found for “{query}”.",
+  "@catalogSearchEmptyForQuery": {"description": "Empty state with search text", "placeholders": {"query": {"type": "String"}}},
+  "catalogSearchEmptyForQueryHint": "Check the spelling or remove filters.",
+  "@catalogSearchEmptyForQueryHint": {"description": "Hint in the empty state with search text"},
+  "catalogSearchEmptyForFilters": "No games match your filters.",
+  "@catalogSearchEmptyForFilters": {"description": "Empty state with filters only"},
+  "catalogSearchEmptyCatalog": "The catalog is still empty.",
+  "@catalogSearchEmptyCatalog": {"description": "Empty state without search text and filters"},
+  "catalogSearchReportGame": "Report a missing game",
+  "@catalogSearchReportGame": {"description": "Action in the empty state"},
+  "catalogSearchErrorOffline": "No connection. You need internet for the search.",
+  "@catalogSearchErrorOffline": {"description": "Error state: offline"},
+  "catalogSearchErrorGeneric": "Search is not available right now.",
+  "@catalogSearchErrorGeneric": {"description": "Error state: other errors"},
+  "catalogSearchErrorInvalid": "This search is not supported. Change the search text or the filters.",
+  "@catalogSearchErrorInvalid": {"description": "Error state: the backend rejected the input (no retry offered)"}
 }

app/lib/l10n/app_localizations.dart

@@ -601,6 +601,228 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Cover of {title}'**
   String gameCoverLabel(String title);
+
+  /// Title of the catalog search screen and label of the search field/entry button
+  ///
+  /// In en, this message translates to:
+  /// **'Search games'**
+  String get catalogSearchTitle;
+
+  /// Hint text of the search field
+  ///
+  /// In en, this message translates to:
+  /// **'Title or publisher'**
+  String get catalogSearchFieldHint;
+
+  /// Tooltip/label of the clear button of the search field
+  ///
+  /// In en, this message translates to:
+  /// **'Clear search'**
+  String get catalogSearchClear;
+
+  /// Button that opens the filters, with the number of active filters
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =0{Filters} other{Filters ({count})}}'**
+  String catalogSearchFilterButton(int count);
+
+  /// Title of the filter area
+  ///
+  /// In en, this message translates to:
+  /// **'Filters'**
+  String get catalogSearchFilterTitle;
+
+  /// Closes the filter sheet
+  ///
+  /// In en, this message translates to:
+  /// **'Done'**
+  String get catalogSearchFilterDone;
+
+  /// Removes all filters
+  ///
+  /// In en, this message translates to:
+  /// **'Reset filters'**
+  String get catalogSearchFilterReset;
+
+  /// Filter label
+  ///
+  /// In en, this message translates to:
+  /// **'Number of players'**
+  String get catalogSearchFilterPlayers;
+
+  /// Filter value without restriction
+  ///
+  /// In en, this message translates to:
+  /// **'Any'**
+  String get catalogSearchFilterAny;
+
+  /// Filter label
+  ///
+  /// In en, this message translates to:
+  /// **'Play time'**
+  String get catalogSearchFilterDuration;
+
+  /// Filter value: games lasting at most this many minutes
+  ///
+  /// In en, this message translates to:
+  /// **'Up to {minutes} min'**
+  String catalogSearchFilterDurationValue(int minutes);
+
+  /// Filter label
+  ///
+  /// In en, this message translates to:
+  /// **'Age'**
+  String get catalogSearchFilterAge;
+
+  /// Filter value: games suitable for players of this age
+  ///
+  /// In en, this message translates to:
+  /// **'Suitable from age {age}'**
+  String catalogSearchFilterAgeValue(int age);
+
+  /// Filter label
+  ///
+  /// In en, this message translates to:
+  /// **'Genre'**
+  String get catalogSearchFilterGenres;
+
+  /// Filter label
+  ///
+  /// In en, this message translates to:
+  /// **'Mechanic'**
+  String get catalogSearchFilterMechanics;
+
+  /// Error in the genre/mechanic filter
+  ///
+  /// In en, this message translates to:
+  /// **'The options could not be loaded.'**
+  String get catalogSearchTermsError;
+
+  /// Retry button
+  ///
+  /// In en, this message translates to:
+  /// **'Try again'**
+  String get catalogSearchRetry;
+
+  /// Number of hits above the list
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =0{No games} =1{1 game} other{{count} games}}'**
+  String catalogSearchResultCount(int count);
+
+  /// Screen reader announcement after a finished search
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =0{No games found} =1{1 game found} other{{count} games found}}'**
+  String catalogSearchAnnouncement(int count);
+
+  /// Alternative title that matched
+  ///
+  /// In en, this message translates to:
+  /// **'also: {title}'**
+  String catalogSearchAlsoKnownAs(String title);
+
+  /// Number of players of a game
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 player} other{{count} players}}'**
+  String catalogSearchPlayersCount(int count);
+
+  /// Player range of a game
+  ///
+  /// In en, this message translates to:
+  /// **'{min}–{max} players'**
+  String catalogSearchPlayersRange(int min, int max);
+
+  /// Play time of a game
+  ///
+  /// In en, this message translates to:
+  /// **'{minutes} min'**
+  String catalogSearchMinutesSingle(int minutes);
+
+  /// Play time range of a game
+  ///
+  /// In en, this message translates to:
+  /// **'{min}–{max} min'**
+  String catalogSearchMinutesRange(int min, int max);
+
+  /// Minimum age of a game
+  ///
+  /// In en, this message translates to:
+  /// **'ages {age}+'**
+  String catalogSearchMinAge(int age);
+
+  /// Publishers of a game, more than shown
+  ///
+  /// In en, this message translates to:
+  /// **'{names} +{more}'**
+  String catalogSearchPublishersMore(String names, int more);
+
+  /// Button at the end of the list
+  ///
+  /// In en, this message translates to:
+  /// **'Load more'**
+  String get catalogSearchLoadMore;
+
+  /// Spoken label of the loading indicator
+  ///
+  /// In en, this message translates to:
+  /// **'Loading games'**
+  String get catalogSearchLoading;
+
+  /// Error when loading the next page
+  ///
+  /// In en, this message translates to:
+  /// **'More games could not be loaded.'**
+  String get catalogSearchLoadMoreError;
+
+  /// Empty state with search text
+  ///
+  /// In en, this message translates to:
+  /// **'No games found for “{query}”.'**
+  String catalogSearchEmptyForQuery(String query);
+
+  /// Hint in the empty state with search text
+  ///
+  /// In en, this message translates to:
+  /// **'Check the spelling or remove filters.'**
+  String get catalogSearchEmptyForQueryHint;
+
+  /// Empty state with filters only
+  ///
+  /// In en, this message translates to:
+  /// **'No games match your filters.'**
+  String get catalogSearchEmptyForFilters;
+
+  /// Empty state without search text and filters
+  ///
+  /// In en, this message translates to:
+  /// **'The catalog is still empty.'**
+  String get catalogSearchEmptyCatalog;
+
+  /// Action in the empty state
+  ///
+  /// In en, this message translates to:
+  /// **'Report a missing game'**
+  String get catalogSearchReportGame;
+
+  /// Error state: offline
+  ///
+  /// In en, this message translates to:
+  /// **'No connection. You need internet for the search.'**
+  String get catalogSearchErrorOffline;
+
+  /// Error state: other errors
+  ///
+  /// In en, this message translates to:
+  /// **'Search is not available right now.'**
+  String get catalogSearchErrorGeneric;
+
+  /// Error state: the backend rejected the input (no retry offered)
+  ///
+  /// In en, this message translates to:
+  /// **'This search is not supported. Change the search text or the filters.'**
+  String get catalogSearchErrorInvalid;
 }
 
 class _AppLocalizationsDelegate

app/lib/l10n/app_localizations_de.dart

@@ -305,4 +305,181 @@ class AppLocalizationsDe extends AppLocalizations {
   String gameCoverLabel(String title) {
     return 'Cover von $title';
   }
+
+  @override
+  String get catalogSearchTitle => 'Spiele suchen';
+
+  @override
+  String get catalogSearchFieldHint => 'Titel oder Verlag';
+
+  @override
+  String get catalogSearchClear => 'Suchbegriff löschen';
+
+  @override
+  String catalogSearchFilterButton(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: 'Filter ($count)',
+      zero: 'Filter',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String get catalogSearchFilterTitle => 'Filter';
+
+  @override
+  String get catalogSearchFilterDone => 'Fertig';
+
+  @override
+  String get catalogSearchFilterReset => 'Filter zurücksetzen';
+
+  @override
+  String get catalogSearchFilterPlayers => 'Spielerzahl';
+
+  @override
+  String get catalogSearchFilterAny => 'Beliebig';
+
+  @override
+  String get catalogSearchFilterDuration => 'Spieldauer';
+
+  @override
+  String catalogSearchFilterDurationValue(int minutes) {
+    return 'Bis $minutes Min.';
+  }
+
+  @override
+  String get catalogSearchFilterAge => 'Alter';
+
+  @override
+  String catalogSearchFilterAgeValue(int age) {
+    return 'Ab $age Jahren geeignet';
+  }
+
+  @override
+  String get catalogSearchFilterGenres => 'Genre';
+
+  @override
+  String get catalogSearchFilterMechanics => 'Mechanik';
+
+  @override
+  String get catalogSearchTermsError =>
+      'Die Auswahl konnte nicht geladen werden.';
+
+  @override
+  String get catalogSearchRetry => 'Erneut versuchen';
+
+  @override
+  String catalogSearchResultCount(int count) {
+    final intl.NumberFormat countNumberFormat =
+        intl.NumberFormat.decimalPattern(localeName);
+    final String countString = countNumberFormat.format(count);
+
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$countString Spiele',
+      one: '1 Spiel',
+      zero: 'Keine Spiele',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchAnnouncement(int count) {
+    final intl.NumberFormat countNumberFormat =
+        intl.NumberFormat.decimalPattern(localeName);
+    final String countString = countNumberFormat.format(count);
+
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$countString Spiele gefunden',
+      one: '1 Spiel gefunden',
+      zero: 'Keine Spiele gefunden',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchAlsoKnownAs(String title) {
+    return 'auch: $title';
+  }
+
+  @override
+  String catalogSearchPlayersCount(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Spieler',
+      one: '1 Spieler',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchPlayersRange(int min, int max) {
+    return '$min–$max Spieler';
+  }
+
+  @override
+  String catalogSearchMinutesSingle(int minutes) {
+    return '$minutes Min.';
+  }
+
+  @override
+  String catalogSearchMinutesRange(int min, int max) {
+    return '$min–$max Min.';
+  }
+
+  @override
+  String catalogSearchMinAge(int age) {
+    return 'ab $age';
+  }
+
+  @override
+  String catalogSearchPublishersMore(String names, int more) {
+    return '$names +$more';
+  }
+
+  @override
+  String get catalogSearchLoadMore => 'Weitere laden';
+
+  @override
+  String get catalogSearchLoading => 'Treffer werden geladen';
+
+  @override
+  String get catalogSearchLoadMoreError =>
+      'Weitere Treffer konnten nicht geladen werden.';
+
+  @override
+  String catalogSearchEmptyForQuery(String query) {
+    return 'Keine Spiele zu „$query“ gefunden.';
+  }
+
+  @override
+  String get catalogSearchEmptyForQueryHint =>
+      'Prüfe die Schreibweise oder entferne Filter.';
+
+  @override
+  String get catalogSearchEmptyForFilters =>
+      'Keine Spiele passen zu deinen Filtern.';
+
+  @override
+  String get catalogSearchEmptyCatalog => 'Der Katalog ist noch leer.';
+
+  @override
+  String get catalogSearchReportGame => 'Fehlendes Spiel melden';
+
+  @override
+  String get catalogSearchErrorOffline =>
+      'Keine Verbindung. Für die Suche brauchst du Internet.';
+
+  @override
+  String get catalogSearchErrorGeneric => 'Die Suche ist gerade nicht möglich.';
+
+  @override
+  String get catalogSearchErrorInvalid =>
+      'Diese Suche wird nicht unterstützt. Ändere den Suchbegriff oder die Filter.';
 }

app/lib/l10n/app_localizations_en.dart

@@ -301,4 +301,178 @@ class AppLocalizationsEn extends AppLocalizations {
   String gameCoverLabel(String title) {
     return 'Cover of $title';
   }
+
+  @override
+  String get catalogSearchTitle => 'Search games';
+
+  @override
+  String get catalogSearchFieldHint => 'Title or publisher';
+
+  @override
+  String get catalogSearchClear => 'Clear search';
+
+  @override
+  String catalogSearchFilterButton(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: 'Filters ($count)',
+      zero: 'Filters',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String get catalogSearchFilterTitle => 'Filters';
+
+  @override
+  String get catalogSearchFilterDone => 'Done';
+
+  @override
+  String get catalogSearchFilterReset => 'Reset filters';
+
+  @override
+  String get catalogSearchFilterPlayers => 'Number of players';
+
+  @override
+  String get catalogSearchFilterAny => 'Any';
+
+  @override
+  String get catalogSearchFilterDuration => 'Play time';
+
+  @override
+  String catalogSearchFilterDurationValue(int minutes) {
+    return 'Up to $minutes min';
+  }
+
+  @override
+  String get catalogSearchFilterAge => 'Age';
+
+  @override
+  String catalogSearchFilterAgeValue(int age) {
+    return 'Suitable from age $age';
+  }
+
+  @override
+  String get catalogSearchFilterGenres => 'Genre';
+
+  @override
+  String get catalogSearchFilterMechanics => 'Mechanic';
+
+  @override
+  String get catalogSearchTermsError => 'The options could not be loaded.';
+
+  @override
+  String get catalogSearchRetry => 'Try again';
+
+  @override
+  String catalogSearchResultCount(int count) {
+    final intl.NumberFormat countNumberFormat =
+        intl.NumberFormat.decimalPattern(localeName);
+    final String countString = countNumberFormat.format(count);
+
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$countString games',
+      one: '1 game',
+      zero: 'No games',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchAnnouncement(int count) {
+    final intl.NumberFormat countNumberFormat =
+        intl.NumberFormat.decimalPattern(localeName);
+    final String countString = countNumberFormat.format(count);
+
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$countString games found',
+      one: '1 game found',
+      zero: 'No games found',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchAlsoKnownAs(String title) {
+    return 'also: $title';
+  }
+
+  @override
+  String catalogSearchPlayersCount(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count players',
+      one: '1 player',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String catalogSearchPlayersRange(int min, int max) {
+    return '$min–$max players';
+  }
+
+  @override
+  String catalogSearchMinutesSingle(int minutes) {
+    return '$minutes min';
+  }
+
+  @override
+  String catalogSearchMinutesRange(int min, int max) {
+    return '$min–$max min';
+  }
+
+  @override
+  String catalogSearchMinAge(int age) {
+    return 'ages $age+';
+  }
+
+  @override
+  String catalogSearchPublishersMore(String names, int more) {
+    return '$names +$more';
+  }
+
+  @override
+  String get catalogSearchLoadMore => 'Load more';
+
+  @override
+  String get catalogSearchLoading => 'Loading games';
+
+  @override
+  String get catalogSearchLoadMoreError => 'More games could not be loaded.';
+
+  @override
+  String catalogSearchEmptyForQuery(String query) {
+    return 'No games found for “$query”.';
+  }
+
+  @override
+  String get catalogSearchEmptyForQueryHint =>
+      'Check the spelling or remove filters.';
+
+  @override
+  String get catalogSearchEmptyForFilters => 'No games match your filters.';
+
+  @override
+  String get catalogSearchEmptyCatalog => 'The catalog is still empty.';
+
+  @override
+  String get catalogSearchReportGame => 'Report a missing game';
+
+  @override
+  String get catalogSearchErrorOffline =>
+      'No connection. You need internet for the search.';
+
+  @override
+  String get catalogSearchErrorGeneric => 'Search is not available right now.';
+
+  @override
+  String get catalogSearchErrorInvalid =>
+      'This search is not supported. Change the search text or the filters.';
 }

app/test/core/logging/app_logger_test.dart

@@ -29,4 +29,19 @@ void main() {
     expect(records.last.level, Level.SEVERE);
     expect(records.last.loggerName, 'Test');
   });
+
+  test('QUE-04: Supabase library records below INFO are not written', () {
+    expect(
+      AppLogger.shouldWrite(LogRecord(Level.FINE, 'x', 'supabase.postgrest')),
+      isFalse,
+    );
+    expect(
+      AppLogger.shouldWrite(LogRecord(Level.WARNING, 'x', 'supabase.auth')),
+      isTrue,
+    );
+    expect(
+      AppLogger.shouldWrite(LogRecord(Level.FINE, 'x', 'CatalogRepository')),
+      isTrue,
+    );
+  });
 }

app/test/core/widgets/app_state_message_test.dart

@@ -0,0 +1,164 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/core/widgets/app_list_footer.dart';
+import 'package:shuffle/core/widgets/app_state_message.dart';
+
+import '../../helpers/pump_app.dart';
+
+void main() {
+  group('AppStateMessage', () {
+    Future<void> pumpMessage(
+      WidgetTester tester, {
+      String? message,
+      List<AppStateAction> actions = const [],
+      ThemeMode themeMode = ThemeMode.light,
+      double? textScale,
+    }) => pumpApp(
+      tester,
+      themeMode: themeMode,
+      textScale: textScale,
+      home: Scaffold(
+        body: AppStateMessage(
+          icon: Icons.search_off,
+          title: 'Nichts gefunden',
+          message: message,
+          actions: actions,
+        ),
+      ),
+    );
+
+    testWidgets('shows title, hint and actions', (tester) async {
+      var pressed = 0;
+      await pumpMessage(
+        tester,
+        message: 'Prüfe die Schreibweise.',
+        actions: [
+          AppStateAction(
+            key: const Key('first'),
+            label: 'Erneut versuchen',
+            onPressed: () => pressed++,
+          ),
+          AppStateAction(label: 'Zurücksetzen', onPressed: () {}),
+        ],
+      );
+
+      expect(find.text('Nichts gefunden'), findsOneWidget);
+      expect(find.text('Prüfe die Schreibweise.'), findsOneWidget);
+      await tester.tap(find.byKey(const Key('first')));
+      expect(pressed, 1);
+      expect(find.text('Zurücksetzen'), findsOneWidget);
+    });
+
+    testWidgets('without hint and actions it is just icon and title', (
+      tester,
+    ) async {
+      await pumpMessage(tester);
+
+      expect(find.byType(FilledButton), findsNothing);
+      expect(find.byType(OutlinedButton), findsNothing);
+    });
+
+    for (final mode in ThemeMode.values.where((m) => m != ThemeMode.system)) {
+      testWidgets('meets accessibility guidelines ($mode)', (tester) async {
+        final handle = tester.ensureSemantics();
+        await pumpMessage(
+          tester,
+          message: 'Hinweis',
+          themeMode: mode,
+          actions: [
+            AppStateAction(label: 'Erneut versuchen', onPressed: () {}),
+            AppStateAction(label: 'Zurücksetzen', onPressed: () {}),
+          ],
+        );
+
+        await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
+        await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
+        await expectLater(tester, meetsGuideline(textContrastGuideline));
+        handle.dispose();
+      });
+    }
+
+    testWidgets('text scale 2.0 does not overflow', (tester) async {
+      await pumpMessage(
+        tester,
+        message: 'Ein längerer Hinweis, der umbrechen muss.',
+        textScale: 2,
+        actions: [AppStateAction(label: 'Erneut versuchen', onPressed: () {})],
+      );
+
+      expect(tester.takeException(), isNull);
+    });
+  });
+
+  group('AppListFooter', () {
+    Future<void> pumpFooter(
+      WidgetTester tester, {
+      bool isLoading = false,
+      bool hasMore = false,
+      String? errorMessage,
+      VoidCallback? onLoadMore,
+      VoidCallback? onRetry,
+    }) => pumpApp(
+      tester,
+      home: Scaffold(
+        body: AppListFooter(
+          isLoading: isLoading,
+          hasMore: hasMore,
+          errorMessage: errorMessage,
+          loadingLabel: 'Lädt',
+          loadMoreLabel: 'Weitere laden',
+          retryLabel: 'Erneut versuchen',
+          onLoadMore: onLoadMore ?? () {},
+          onRetry: onRetry ?? () {},
+        ),
+      ),
+      settle: false,
+    );
+
+    testWidgets('shows the load-more button while more is available', (
+      tester,
+    ) async {
+      var loads = 0;
+      await pumpFooter(tester, hasMore: true, onLoadMore: () => loads++);
+
+      await tester.tap(find.text('Weitere laden'));
+
+      expect(loads, 1);
+    });
+
+    testWidgets('shows a labeled indicator while loading', (tester) async {
+      final handle = tester.ensureSemantics();
+      await pumpFooter(tester, hasMore: true, isLoading: true);
+
+      expect(find.byKey(const Key('list_footer_loading')), findsOneWidget);
+      expect(find.text('Weitere laden'), findsNothing);
+      expect(find.bySemanticsLabel('Lädt'), findsOneWidget);
+      handle.dispose();
+    });
+
+    testWidgets('shows the error with retry, ahead of everything else', (
+      tester,
+    ) async {
+      var retries = 0;
+      await pumpFooter(
+        tester,
+        hasMore: true,
+        isLoading: true,
+        errorMessage: 'Fehler beim Laden',
+        onRetry: () => retries++,
+      );
+
+      expect(find.text('Fehler beim Laden'), findsOneWidget);
+      await tester.tap(find.byKey(const Key('list_footer_retry')));
+      expect(retries, 1);
+      expect(find.byKey(const Key('list_footer_loading')), findsNothing);
+    });
+
+    testWidgets('shows nothing at the end of the list', (tester) async {
+      await pumpFooter(tester);
+
+      expect(find.byType(OutlinedButton), findsNothing);
+      expect(find.byKey(const Key('list_footer_loading')), findsNothing);
+    });
+  });
+}

app/test/features/catalog/catalog_test_support.dart

@@ -0,0 +1,152 @@
+import 'dart:async';
+
+import 'package:flutter_riverpod/misc.dart' show Override;
+import 'package:shuffle/core/result/result.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_game_summary.dart';
+import 'package:shuffle/features/catalog/domain/catalog_repository.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_page.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+import 'package:shuffle/features/catalog/presentation/providers/catalog_providers.dart';
+
+import '../../helpers/fakes.dart';
+
+/// UUIDs for filter tests.
+const genreStrategy = '11111111-1111-4111-8111-111111111111';
+const genreFamily = '22222222-2222-4222-8222-222222222222';
+const mechanicDice = '33333333-3333-4333-8333-333333333333';
+const mechanicCards = '44444444-4444-4444-8444-444444444444';
+
+const testGenres = [
+  CatalogTerm(id: genreStrategy, nameDe: 'Strategie', nameEn: 'Strategy'),
+  CatalogTerm(id: genreFamily, nameDe: 'Familie', nameEn: 'Family'),
+];
+
+const testMechanics = [
+  CatalogTerm(id: mechanicDice, nameDe: 'Würfeln', nameEn: 'Dice rolling'),
+];
+
+CatalogGameSummary game(
+  int n, {
+  String? title,
+  int? year = 1995,
+  int? minPlayers = 3,
+  int? maxPlayers = 4,
+  int? minMinutes = 60,
+  int? maxMinutes = 120,
+  int? minAge = 10,
+  List<String> publishers = const ['Kosmos'],
+  String? matchedAltTitle,
+}) => CatalogGameSummary(
+  id: 'game-$n',
+  title: title ?? 'Spiel $n',
+  year: year,
+  minPlayers: minPlayers,
+  maxPlayers: maxPlayers,
+  minMinutes: minMinutes,
+  maxMinutes: maxMinutes,
+  minAge: minAge,
+  publisherNames: publishers,
+  matchedAltTitle: matchedAltTitle,
+);
+
+/// One recorded call of [FakeCatalogRepository.search].
+class SearchCall {
+  SearchCall(this.query, this.offset, this.limit, this.completer);
+
+  final CatalogSearchQuery query;
+  final int offset;
+  final int limit;
+  final Completer<Result<CatalogSearchPage, CatalogFailure>> completer;
+}
+
+/// Fake [CatalogRepository]. By default it answers at once from [all] (a
+/// list of games it filters by nothing but pages by offset/limit). With
+/// [manual] every search waits until the test completes it.
+class FakeCatalogRepository implements CatalogRepository {
+  FakeCatalogRepository({
+    this.all = const [],
+    this.manual = false,
+    this.genres = testGenres,
+    this.mechanics = testMechanics,
+  });
+
+  List<CatalogGameSummary> all;
+  bool manual;
+  List<CatalogTerm> genres;
+  List<CatalogTerm> mechanics;
+
+  /// Failure to return instead of results (null = none).
+  CatalogFailure? failWith;
+  CatalogFailure? termsFailWith;
+
+  final List<SearchCall> calls = [];
+
+  @override
+  Future<Result<CatalogSearchPage, CatalogFailure>> search(
+    CatalogSearchQuery query, {
+    required int offset,
+    int limit = CatalogSearchLimits.pageSize,
+  }) {
+    final completer = Completer<Result<CatalogSearchPage, CatalogFailure>>();
+    final call = SearchCall(query, offset, limit, completer);
+    calls.add(call);
+    if (!manual) {
+      completer.complete(_answer(offset, limit));
+    }
+    return completer.future;
+  }
+
+  Result<CatalogSearchPage, CatalogFailure> _answer(int offset, int limit) {
+    final failure = failWith;
+    if (failure != null) {
+      return Result.failure(failure);
+    }
+    final end = (offset + limit).clamp(0, all.length);
+    final start = offset.clamp(0, all.length);
+    return Result.success(
+      CatalogSearchPage(items: all.sublist(start, end), totalCount: all.length),
+    );
+  }
+
+  /// Completes the pending call [index] (manual mode).
+  void complete(
+    int index, {
+    List<CatalogGameSummary>? items,
+    int? totalCount,
+    CatalogFailure? failure,
+  }) {
+    final call = calls[index];
+    if (failure != null) {
+      call.completer.complete(Result.failure(failure));
+      return;
+    }
+    final list = items ?? all;
+    call.completer.complete(
+      Result.success(
+        CatalogSearchPage(items: list, totalCount: totalCount ?? list.length),
+      ),
+    );
+  }
+
+  @override
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchGenres() async {
+    final failure = termsFailWith;
+    return failure != null ? Result.failure(failure) : Result.success(genres);
+  }
+
+  @override
+  Future<Result<List<CatalogTerm>, CatalogFailure>> fetchMechanics() async {
+    final failure = termsFailWith;
+    return failure != null
+        ? Result.failure(failure)
+        : Result.success(mechanics);
+  }
+}
+
+/// Overrides with [repository] as catalog repository.
+List<Override> catalogOverrides(FakeCatalogRepository repository) => [
+  ...testOverrides(),
+  catalogRepositoryProvider.overrideWithValue(repository),
+];

app/test/features/catalog/data/supabase_catalog_repository_test.dart

@@ -0,0 +1,352 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
+import 'package:logging/logging.dart';
+import 'package:shuffle/core/logging/app_logger.dart';
+import 'package:shuffle/features/catalog/data/supabase_catalog_repository.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:supabase_flutter/supabase_flutter.dart';
+
+import '../catalog_test_support.dart';
+
+/// Tests the repository with a real [SupabaseClient] whose HTTP layer is a
+/// fake: the requests that would reach the backend are recorded. The real RPC
+/// (backend 3a) is not part of these tests.
+void main() {
+  late List<http.Request> requests;
+  late SupabaseClient client;
+  late http.Response Function(http.Request) respond;
+  late SupabaseCatalogRepository repository;
+
+  setUp(() {
+    requests = [];
+    respond = (request) => http.Response('[]', 200);
+    client = SupabaseClient(
+      'http://localhost:54321',
+      'anon-key',
+      httpClient: MockClient((request) async {
+        requests.add(request);
+        final response = respond(request);
+        // The postgrest parser reads `response.request`.
+        return http.Response.bytes(
+          response.bodyBytes,
+          response.statusCode,
+          headers: response.headers,
+          request: request,
+        );
+      }),
+    );
+    repository = SupabaseCatalogRepository(client);
+  });
+
+  tearDown(() async {
+    await client.dispose();
+  });
+
+  Map<String, dynamic> body(http.Request request) =>
+      jsonDecode(request.body) as Map<String, dynamic>;
+
+  Map<String, dynamic> row(int n, {int total = 2}) => {
+    'id': 'game-$n',
+    'title': 'Spiel $n',
+    'year': 1995,
+    'min_players': 3,
+    'max_players': 4,
+    'min_minutes': 60,
+    'max_minutes': 120,
+    'min_age': 10,
+    'image_path': null,
+    'publisher_names': ['Kosmos'],
+    'matched_alt_title': null,
+    'match_rank': 1,
+    'total_count': total,
+  };
+
+  group('search parameters', () {
+    test('KAT-01 Kriterium 1: sends the text and paging via POST', () async {
+      await repository.search(
+        const CatalogSearchQuery(text: 'catan'),
+        offset: 30,
+      );
+
+      expect(requests, hasLength(1));
+      final request = requests.single;
+      expect(request.method, 'POST');
+      expect(request.url.path, '/rest/v1/rpc/search_catalog_games');
+      // The search text is never part of the URL (privacy).
+      expect(request.url.toString(), isNot(contains('catan')));
+      expect(body(request), {
+        'p_query': 'catan',
+        'p_limit': 30,
+        'p_offset': 30,
+      });
+    });
+
+    test('KAT-01 Kriterium 1: text below 2 characters is not sent', () async {
+      await repository.search(const CatalogSearchQuery(text: 'c'), offset: 0);
+
+      expect(body(requests.single), {'p_limit': 30, 'p_offset': 0});
+    });
+
+    test(
+      'KAT-01 Kriterium 8: no filters and no text sends paging only',
+      () async {
+        await repository.search(const CatalogSearchQuery(), offset: 0);
+
+        expect(body(requests.single), {'p_limit': 30, 'p_offset': 0});
+      },
+    );
+
+    test('KAT-01 Kriterium 4: sends all set filters, no empty sets', () async {
+      await repository.search(
+        const CatalogSearchQuery(
+          filters: CatalogFilters(
+            players: 4,
+            maxMinutes: 60,
+            minAgeSuitable: 10,
+            genreIds: {genreStrategy},
+          ),
+        ),
+        offset: 0,
+        limit: 10,
+      );
+
+      expect(body(requests.single), {
+        'p_players': 4,
+        'p_max_minutes': 60,
+        'p_age': 10,
+        'p_genre_ids': [genreStrategy],
+        'p_limit': 10,
+        'p_offset': 0,
+      });
+      expect(body(requests.single), isNot(contains('p_mechanic_ids')));
+    });
+
+    test(
+      'KAT-01 Kriterium 4: several genre and mechanic IDs are all sent',
+      () async {
+        await repository.search(
+          const CatalogSearchQuery(
+            filters: CatalogFilters(
+              genreIds: {genreStrategy, genreFamily},
+              mechanicIds: {mechanicDice, mechanicCards},
+            ),
+          ),
+          offset: 0,
+        );
+
+        final sent = body(requests.single);
+        expect(
+          sent['p_genre_ids'],
+          unorderedEquals([genreStrategy, genreFamily]),
+        );
+        expect(
+          sent['p_mechanic_ids'],
+          unorderedEquals([mechanicDice, mechanicCards]),
+        );
+      },
+    );
+
+    test('KAT-01 Kriterium 4: mechanics are sent as p_mechanic_ids', () async {
+      await repository.search(
+        const CatalogSearchQuery(
+          filters: CatalogFilters(mechanicIds: {mechanicDice}),
+        ),
+        offset: 0,
+      );
+
+      expect(body(requests.single)['p_mechanic_ids'], [mechanicDice]);
+    });
+  });
+
+  group('search result', () {
+    test('KAT-01 Kriterium 1: parses rows and the total count', () async {
+      respond = (request) => http.Response(
+        jsonEncode([row(1, total: 42), row(2, total: 42)]),
+        200,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.search(
+        const CatalogSearchQuery(text: 'spiel'),
+        offset: 0,
+      );
+
+      final page = result.valueOrNull!;
+      expect(page.totalCount, 42);
+      expect(page.items.map((g) => g.id), ['game-1', 'game-2']);
+      expect(page.items.first.minPlayers, 3);
+      expect(page.items.first.publisherNames, ['Kosmos']);
+    });
+
+    test('no rows give an empty page with total 0', () async {
+      final result = await repository.search(
+        const CatalogSearchQuery(text: 'nichts'),
+        offset: 0,
+      );
+
+      expect(result.valueOrNull!.items, isEmpty);
+      expect(result.valueOrNull!.totalCount, 0);
+    });
+  });
+
+  group('vocabulary', () {
+    test('KAT-01 Kriterium 4: reads genres from the table', () async {
+      respond = (request) => http.Response(
+        jsonEncode([
+          {'id': genreStrategy, 'name_de': 'Strategie', 'name_en': 'Strategy'},
+        ]),
+        200,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.fetchGenres();
+
+      expect(requests.single.method, 'GET');
+      expect(requests.single.url.path, '/rest/v1/genres');
+      expect(result.valueOrNull!.single.nameEn, 'Strategy');
+    });
+
+    test('reads mechanics from the table', () async {
+      await repository.fetchMechanics();
+
+      expect(requests.single.url.path, '/rest/v1/mechanics');
+    });
+
+    test('a failing vocabulary call gives a failure', () async {
+      // (A transport error would be retried by postgrest for several seconds.)
+      respond = (request) => http.Response(
+        jsonEncode({'code': 'XX000', 'message': 'boom'}),
+        500,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.fetchGenres();
+
+      expect(result.errorOrNull, isA<CatalogUnexpectedFailure>());
+    });
+  });
+
+  group('failures', () {
+    test('Zustände Kriterium 3: connection error maps to network', () async {
+      respond = (request) => throw http.ClientException('offline');
+
+      final result = await repository.search(
+        const CatalogSearchQuery(),
+        offset: 0,
+      );
+
+      expect(result.errorOrNull, isA<CatalogNetworkFailure>());
+    });
+
+    test('Zustände Kriterium 3: timeout maps to network', () async {
+      final slow = SupabaseCatalogRepository(
+        SupabaseClient(
+          'http://localhost:54321',
+          'anon-key',
+          httpClient: MockClient((request) {
+            return Completer<http.Response>().future;
+          }),
+        ),
+        timeout: const Duration(milliseconds: 20),
+      );
+
+      final result = await slow.search(const CatalogSearchQuery(), offset: 0);
+
+      expect(result.errorOrNull, isA<CatalogNetworkFailure>());
+    });
+
+    test('P0001 from the RPC maps to invalidInput', () async {
+      respond = (request) => http.Response(
+        jsonEncode({
+          'code': 'P0001',
+          'message': 'search_query_too_long',
+          'details': null,
+          'hint': null,
+        }),
+        400,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.search(
+        const CatalogSearchQuery(text: 'ab'),
+        offset: 0,
+      );
+
+      expect(result.errorOrNull, isA<CatalogInvalidInputFailure>());
+    });
+
+    test('other server errors map to unexpected', () async {
+      respond = (request) => http.Response(
+        jsonEncode({'code': '42501', 'message': 'denied'}),
+        403,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.search(
+        const CatalogSearchQuery(),
+        offset: 0,
+      );
+
+      expect(result.errorOrNull, isA<CatalogUnexpectedFailure>());
+    });
+
+    test('a malformed answer maps to unexpected', () async {
+      respond = (request) => http.Response(
+        '{"not":"a list"}',
+        200,
+        headers: {'content-type': 'application/json'},
+      );
+
+      final result = await repository.search(
+        const CatalogSearchQuery(),
+        offset: 0,
+      );
+
+      expect(result.errorOrNull, isA<CatalogUnexpectedFailure>());
+    });
+
+    test('QUE-04: the repository logger never logs the search text', () async {
+      const secret = 'geheimer-suchbegriff';
+      final records = <LogRecord>[];
+      Logger.root.level = Level.ALL;
+      final subscription = Logger.root.onRecord.listen(records.add);
+      addTearDown(subscription.cancel);
+      // Make the exception text echo the request, as a server might.
+      respond = (request) => http.Response(
+        jsonEncode({'code': 'P0001', 'message': 'bad $secret'}),
+        400,
+        headers: {'content-type': 'application/json'},
+      );
+      AppLogger('probe').debug('probe');
+
+      await repository.search(
+        const CatalogSearchQuery(text: secret),
+        offset: 0,
+      );
+
+      // Any other library may echo the text in its own debug logs (postgrest
+      // does at FINE); AppLogger drops those, so none of them is written.
+      for (final record in records.where(
+        (r) => '${r.message} ${r.error}'.contains(secret),
+      )) {
+        expect(
+          AppLogger.shouldWrite(record),
+          isFalse,
+          reason: '${record.loggerName} would write the search text',
+        );
+      }
+      final catalog = records.where((r) => r.loggerName == 'CatalogRepository');
+      expect(catalog, isNotEmpty);
+      for (final record in catalog) {
+        expect(record.message, isNot(contains(secret)));
+        expect(record.error, isNull);
+        expect(record.stackTrace, isNull);
+      }
+    });
+  });
+}

app/test/features/catalog/domain/catalog_domain_test.dart

@@ -0,0 +1,199 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:shuffle/features/catalog/data/catalog_failure_mapper.dart';
+import 'package:shuffle/features/catalog/data/catalog_game_summary_dto.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_state.dart';
+import 'package:supabase_flutter/supabase_flutter.dart';
+
+import '../catalog_test_support.dart';
+
+void main() {
+  group('CatalogTerm', () {
+    const term = CatalogTerm(id: 'x', nameDe: 'Würfeln', nameEn: 'Dice');
+
+    test('QUE-05 Kriterium 4: German for de, English otherwise', () {
+      expect(term.localizedName('de'), 'Würfeln');
+      expect(term.localizedName('en'), 'Dice');
+      expect(term.localizedName('fr'), 'Dice');
+    });
+  });
+
+  group('CatalogSearchQuery', () {
+    test('KAT-01 Kriterium 1: text counts from 2 characters', () {
+      expect(const CatalogSearchQuery().hasText, isFalse);
+      expect(const CatalogSearchQuery(text: 'c').hasText, isFalse);
+      expect(const CatalogSearchQuery(text: 'ca').hasText, isTrue);
+    });
+
+    test('a text below the minimum is dropped from the effective query', () {
+      expect(const CatalogSearchQuery(text: 'c').effective.text, '');
+      expect(const CatalogSearchQuery(text: 'ca').effective.text, 'ca');
+    });
+
+    test('cleanText trims and cuts to 100 characters', () {
+      expect(CatalogSearchQuery.cleanText('  catan  '), 'catan');
+      expect(CatalogSearchQuery.cleanText('a' * 150), hasLength(100));
+    });
+
+    test(
+      'Eingabegrenzen: the text is cut to 10 words (rest dropped silently)',
+      () {
+        expect(
+          CatalogSearchQuery.cleanText('a b c d e f g h i j k l'),
+          'a b c d e f g h i j',
+        );
+        expect(
+          CatalogSearchQuery.cleanText('a b c d e f g h i j'),
+          'a b c d e f g h i j',
+        );
+        expect(CatalogSearchQuery.cleanText('a b c'), 'a b c');
+      },
+    );
+
+    test('Eingabegrenzen: punctuation separates words like in the backend', () {
+      // Hyphen and colon split words: 12 words, not 6.
+      expect(
+        CatalogSearchQuery.cleanText('a-b c:d e-f g-h i-j k-l'),
+        'a-b c:d e-f g-h i-j',
+      );
+      expect(
+        CatalogSearchQuery.cleanText(
+          'Æon’s End: Ünïcode Wörter ß 1 2 3 4 5 6 7',
+        ),
+        'Æon’s End: Ünïcode Wörter ß 1 2 3 4',
+      );
+    });
+
+    test('KAT-01 Kriterium 4: activeFilterCount counts every filter value', () {
+      const filters = CatalogFilters(
+        players: 3,
+        maxMinutes: 60,
+        minAgeSuitable: 8,
+        genreIds: {genreStrategy, genreFamily},
+        mechanicIds: {mechanicDice},
+      );
+
+      expect(filters.activeCount, 6);
+      expect(const CatalogFilters().isEmpty, isTrue);
+      expect(const CatalogSearchQuery(filters: filters).hasFilters, isTrue);
+    });
+
+    test('KAT-01 Kriterium 8: no text and no filters is the whole catalog', () {
+      expect(const CatalogSearchQuery().isEmpty, isTrue);
+      expect(const CatalogSearchQuery(text: 'x').isEmpty, isTrue);
+      expect(const CatalogSearchQuery(text: 'xx').isEmpty, isFalse);
+    });
+
+    test('Eingabegrenzen: out-of-range values are rejected', () {
+      expect(() => CatalogFilters(players: 0), throwsA(isA<AssertionError>()));
+      expect(() => CatalogFilters(players: 13), throwsA(isA<AssertionError>()));
+      expect(
+        () => CatalogSearchQuery(text: 'a' * 101),
+        throwsA(isA<AssertionError>()),
+      );
+    });
+  });
+
+  group('CatalogSearchState', () {
+    test('KAT-01 Kriterium 5: hasMore compares items and total', () {
+      final state = CatalogSearchState(items: [game(1)], totalCount: 2);
+
+      expect(state.hasMore, isTrue);
+      expect(state.copyWith(totalCount: 1).hasMore, isFalse);
+    });
+
+    test('KAT-01 Kriterium 5: no more pages beyond offset 10000', () {
+      final state = CatalogSearchState(
+        items: List.generate(10000, game),
+        totalCount: 20000,
+      );
+
+      expect(state.hasMore, isFalse);
+    });
+  });
+
+  group('CatalogGameSummaryDto', () {
+    test('KAT-01 Kriterium 2: parses matched_alt_title and numbers', () {
+      final dto = CatalogGameSummaryDto.fromJson({
+        'id': 'a',
+        'title': 'Catan',
+        'year': 1995,
+        'min_players': 3.0,
+        'max_players': 4,
+        'min_minutes': null,
+        'max_minutes': null,
+        'min_age': 10,
+        'image_path': null,
+        'publisher_names': ['Kosmos', 'Franckh'],
+        'matched_alt_title': 'Die Siedler von Catan',
+        'match_rank': 0,
+        'total_count': 12,
+      });
+
+      final game = dto.toDomain();
+      expect(game.matchedAltTitle, 'Die Siedler von Catan');
+      expect(game.minPlayers, 3);
+      expect(game.minMinutes, isNull);
+      expect(game.publisherNames, ['Kosmos', 'Franckh']);
+    });
+
+    test('all optional fields may be missing, publisher_names is empty', () {
+      final game = CatalogGameSummaryDto.fromJson({
+        'id': 'a',
+        'title': 'Catan',
+        'publisher_names': null,
+      }).toDomain();
+
+      expect(game.year, isNull);
+      expect(game.imagePath, isNull);
+      expect(game.publisherNames, isEmpty);
+    });
+  });
+
+  group('mapCatalogError', () {
+    test('Zustände Kriterium 3: transport errors and timeouts are network', () {
+      expect(
+        mapCatalogError(TimeoutException('slow')),
+        isA<CatalogNetworkFailure>(),
+      );
+      expect(
+        mapCatalogError(const SocketException('down')),
+        isA<CatalogNetworkFailure>(),
+      );
+      expect(
+        mapCatalogError(http.ClientException('down')),
+        isA<CatalogNetworkFailure>(),
+      );
+    });
+
+    test('P0001 is invalidInput, other Postgrest errors are unexpected', () {
+      expect(
+        mapCatalogError(
+          const PostgrestException(
+            message: 'search_filter_invalid',
+            code: 'P0001',
+          ),
+        ),
+        isA<CatalogInvalidInputFailure>(),
+      );
+      for (final code in ['22003', '22P02']) {
+        expect(
+          mapCatalogError(PostgrestException(message: 'x', code: code)),
+          isA<CatalogInvalidInputFailure>(),
+          reason: code,
+        );
+      }
+      expect(
+        mapCatalogError(const PostgrestException(message: 'x', code: '42501')),
+        isA<CatalogUnexpectedFailure>(),
+      );
+      expect(mapCatalogError(StateError('x')), isA<CatalogUnexpectedFailure>());
+    });
+  });
+}

app/test/features/catalog/presentation/catalog_query_params_test.dart

@@ -0,0 +1,77 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/catalog_query_params.dart';
+
+import '../catalog_test_support.dart';
+
+void main() {
+  test('KAT-01 Kriterium 4: URL round trip keeps text and all filters', () {
+    const query = CatalogSearchQuery(
+      text: 'catan kosmos',
+      filters: CatalogFilters(
+        players: 4,
+        maxMinutes: 90,
+        minAgeSuitable: 12,
+        genreIds: {genreStrategy, genreFamily},
+        mechanicIds: {mechanicDice},
+      ),
+    );
+
+    final params = catalogQueryParameters(query);
+    final uri = catalogLocation('/catalog', query);
+    final parsed = parseCatalogQuery(uri.queryParameters);
+
+    expect(params['q'], 'catan kosmos');
+    expect(parsed, query);
+  });
+
+  test('an empty query has no parameters and no query string', () {
+    expect(catalogQueryParameters(const CatalogSearchQuery()), isEmpty);
+    expect(
+      catalogLocation('/catalog', const CatalogSearchQuery()).toString(),
+      '/catalog',
+    );
+  });
+
+  test('special characters in the text survive the URL', () {
+    const query = CatalogSearchQuery(text: 'Æon’s End & Co/ä?');
+
+    final uri = Uri.parse(catalogLocation('/catalog', query).toString());
+
+    expect(parseCatalogQuery(uri.queryParameters), query);
+  });
+
+  test('invalid or unknown values are ignored silently', () {
+    final parsed = parseCatalogQuery({
+      'players': '13',
+      'maxMinutes': '75',
+      'age': 'abc',
+      'genre': 'not-a-uuid,$genreStrategy',
+      'mechanic': ',,',
+      'unknown': 'x',
+    });
+
+    expect(parsed.filters.players, isNull);
+    expect(parsed.filters.maxMinutes, isNull);
+    expect(parsed.filters.minAgeSuitable, isNull);
+    expect(parsed.filters.genreIds, {genreStrategy});
+    expect(parsed.filters.mechanicIds, isEmpty);
+  });
+
+  test('Eingabegrenzen: text is trimmed and cut to 100 characters', () {
+    final parsed = parseCatalogQuery({'q': '  ${'a' * 150}  '});
+
+    expect(parsed.text, hasLength(100));
+  });
+
+  test('Eingabegrenzen: at most 20 genre IDs are taken', () {
+    final ids = [
+      for (var i = 0; i < 30; i++)
+        '00000000-0000-4000-8000-${i.toString().padLeft(12, '0')}',
+    ];
+
+    final parsed = parseCatalogQuery({'genre': ids.join(',')});
+
+    expect(parsed.filters.genreIds, hasLength(20));
+  });
+}

app/test/features/catalog/presentation/search/catalog_search_a11y_test.dart

@@ -0,0 +1,162 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+
+import '../../catalog_test_support.dart';
+import 'catalog_search_test_support.dart';
+
+void main() {
+  group('announcements', () {
+    testWidgets('QUE-06 Kriterium 2: the hit count is announced once', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: List.generate(75, game));
+      await pumpView(tester, repository);
+      tester.takeAnnouncements();
+
+      await tester.enterText(searchInput, 'spiel');
+      await tester.testTextInput.receiveAction(TextInputAction.search);
+      await tester.pump();
+      // Not at once: the announcement waits for a quiet moment.
+      expect(tester.takeAnnouncements(), isEmpty);
+
+      await tester.pump(const Duration(seconds: 1));
+
+      final messages = tester.takeAnnouncements().map((a) => a.message);
+      expect(messages, ['75 Spiele gefunden']);
+    });
+
+    testWidgets('QUE-06 Kriterium 2: nothing is announced while typing', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: List.generate(75, game));
+      await pumpView(tester, repository);
+      await tester.pump(const Duration(seconds: 1));
+      tester.takeAnnouncements();
+
+      await tester.enterText(searchInput, 'sp');
+      await tester.pump(const Duration(milliseconds: 100));
+      await tester.enterText(searchInput, 'spi');
+      await tester.pump(const Duration(milliseconds: 100));
+
+      expect(tester.takeAnnouncements(), isEmpty);
+      // Let the pending search run out before the test ends.
+      await tester.pump(const Duration(seconds: 2));
+    });
+
+    testWidgets('quick filter changes give one announcement (debounced)', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await tester.pump(const Duration(seconds: 1));
+      tester.takeAnnouncements();
+      await tester.tap(find.byKey(const Key('catalog_filter_button')));
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.byKey(const Key('catalog_term_$genreStrategy')));
+      await tester.pump(const Duration(milliseconds: 100));
+      await tester.tap(find.byKey(const Key('catalog_term_$genreFamily')));
+      await tester.pump(const Duration(milliseconds: 100));
+      await tester.tap(find.byKey(const Key('catalog_term_$mechanicDice')));
+      await tester.pump(const Duration(seconds: 1));
+
+      final messages = tester.takeAnnouncements().map((a) => a.message);
+      expect(messages, ['1 Spiel gefunden']);
+    });
+
+    testWidgets('an empty result is announced as well', (tester) async {
+      final repository = FakeCatalogRepository();
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'zzz'),
+      );
+
+      await tester.pump(const Duration(seconds: 1));
+
+      final messages = tester.takeAnnouncements().map((a) => a.message);
+      expect(messages, contains('Keine Spiele gefunden'));
+    });
+
+    testWidgets('English announcement', (tester) async {
+      final repository = FakeCatalogRepository(all: List.generate(2, game));
+      await pumpView(tester, repository, locale: const Locale('en'));
+
+      await tester.pump(const Duration(seconds: 1));
+
+      final messages = tester.takeAnnouncements().map((a) => a.message);
+      expect(messages, contains('2 games found'));
+    });
+  });
+
+  group('accessibility guidelines (QUE-06 Kriterium 1, 3)', () {
+    Future<void> check(WidgetTester tester, {double width = 420}) async {
+      final handle = tester.ensureSemantics();
+      final repository = FakeCatalogRepository(
+        all: [
+          game(1, matchedAltTitle: 'Alternativtitel'),
+          game(2, publishers: ['A', 'B', 'C']),
+        ],
+      );
+      await pumpView(
+        tester,
+        repository,
+        width: width,
+        initialQuery: const CatalogSearchQuery(text: 'spiel'),
+      );
+
+      await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(iOSTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(textContrastGuideline));
+      handle.dispose();
+    }
+
+    testWidgets('compact layout', check);
+    testWidgets('expanded layout with side bar', (tester) async {
+      await check(tester, width: 1200);
+    });
+
+    testWidgets('filter sheet', (tester) async {
+      final handle = tester.ensureSemantics();
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await tester.tap(find.byKey(const Key('catalog_filter_button')));
+      await tester.pumpAndSettle();
+
+      await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(textContrastGuideline));
+      handle.dispose();
+    });
+
+    testWidgets('empty and error states', (tester) async {
+      final handle = tester.ensureSemantics();
+      final repository = FakeCatalogRepository();
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(
+          text: 'zzz',
+          filters: CatalogFilters(players: 2),
+        ),
+      );
+
+      await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
+      await expectLater(tester, meetsGuideline(textContrastGuideline));
+      handle.dispose();
+    });
+
+    testWidgets('search field is labeled for screen readers', (tester) async {
+      final handle = tester.ensureSemantics();
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+
+      expect(find.bySemanticsLabel('Spiele suchen'), findsWidgets);
+      expect(find.bySemanticsLabel('Suchbegriff löschen'), findsNothing);
+      handle.dispose();
+    });
+  });
+}

app/test/features/catalog/presentation/search/catalog_search_behavior_test.dart

@@ -0,0 +1,494 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/domain/catalog_term.dart';
+
+import '../../catalog_test_support.dart';
+import 'catalog_search_test_support.dart';
+
+Future<void> openFilterSheet(WidgetTester tester) async {
+  await tester.tap(find.byKey(const Key('catalog_filter_button')));
+  await tester.pumpAndSettle();
+}
+
+void main() {
+  group('filters in the bottom sheet (compact)', () {
+    testWidgets('KAT-01 Kriterium 4: the button shows the number of filters', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(
+          filters: CatalogFilters(players: 2, genreIds: {genreFamily}),
+        ),
+      );
+
+      expect(find.text('Filter (2)'), findsOneWidget);
+    });
+
+    testWidgets('the button shows plain "Filter" without filters', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(tester, repository);
+
+      expect(find.text('Filter'), findsOneWidget);
+    });
+
+    testWidgets('KAT-01 Kriterium 4: each filter kind sets its value', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      Future<void> pick(String fieldKey, String label) async {
+        await tester.tap(find.byKey(Key(fieldKey)));
+        await tester.pumpAndSettle();
+        await tester.tap(find.text(label).last);
+        await tester.pumpAndSettle();
+      }
+
+      await pick('catalog_filter_players', '4 Spieler');
+      await pick('catalog_filter_duration', 'Bis 60 Min.');
+      await pick('catalog_filter_age', 'Ab 10 Jahren geeignet');
+      await tester.tap(find.byKey(const Key('catalog_term_$genreStrategy')));
+      await tester.pumpAndSettle();
+      await tester.tap(find.byKey(const Key('catalog_term_$mechanicDice')));
+      await tester.pumpAndSettle();
+
+      final filters = repository.calls.last.query.filters;
+      expect(filters.players, 4);
+      expect(filters.maxMinutes, 60);
+      expect(filters.minAgeSuitable, 10);
+      expect(filters.genreIds, {genreStrategy});
+      expect(filters.mechanicIds, {mechanicDice});
+      // The list behind the sheet updates immediately.
+      expect(repository.calls.length, greaterThan(5));
+    });
+
+    testWidgets('KAT-01 Kriterium 4: two genres are both sent (AND)', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      await tester.tap(find.byKey(const Key('catalog_term_$genreStrategy')));
+      await tester.pumpAndSettle();
+      await tester.tap(find.byKey(const Key('catalog_term_$genreFamily')));
+      await tester.pumpAndSettle();
+
+      expect(repository.calls.last.query.filters.genreIds, {
+        genreStrategy,
+        genreFamily,
+      });
+    });
+
+    testWidgets('KAT-01 Kriterium 4: a chip can be deselected again', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      await tester.tap(find.byKey(const Key('catalog_term_$genreStrategy')));
+      await tester.pumpAndSettle();
+      await tester.tap(find.byKey(const Key('catalog_term_$genreStrategy')));
+      await tester.pumpAndSettle();
+
+      expect(repository.calls.last.query.filters.genreIds, isEmpty);
+    });
+
+    testWidgets('reset removes all filters and Done closes the sheet', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(
+          filters: CatalogFilters(players: 2, genreIds: {genreFamily}),
+        ),
+      );
+      await openFilterSheet(tester);
+
+      await tester.tap(find.byKey(const Key('catalog_filter_reset')));
+      await tester.pumpAndSettle();
+      expect(repository.calls.last.query.hasFilters, isFalse);
+
+      await tester.tap(find.byKey(const Key('catalog_filter_done')));
+      await tester.pumpAndSettle();
+      expect(find.byKey(const Key('catalog_filter_sheet')), findsNothing);
+      expect(find.text('Filter'), findsWidgets);
+    });
+
+    testWidgets('QUE-05 Kriterium 4: terms are named and sorted by language', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      // German: Familie before Strategie.
+      expect(find.text('Familie'), findsOneWidget);
+      final de = tester.getTopLeft(find.text('Familie')).dx;
+      final de2 = tester.getTopLeft(find.text('Strategie')).dx;
+      expect(de, lessThan(de2));
+    });
+
+    testWidgets('terms with umlauts sort next to their base letters', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(
+        all: [game(1)],
+        genres: const [
+          CatalogTerm(id: genreStrategy, nameDe: 'Zocken', nameEn: 'Z'),
+          CatalogTerm(id: genreFamily, nameDe: 'Ökonomie', nameEn: 'E'),
+          CatalogTerm(
+            id: '55555555-5555-4555-8555-555555555555',
+            nameDe: 'Party',
+            nameEn: 'P',
+          ),
+        ],
+      );
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      final party = tester.getTopLeft(find.text('Party'));
+      final oekonomie = tester.getTopLeft(find.text('Ökonomie'));
+      final zocken = tester.getTopLeft(find.text('Zocken'));
+      bool before(Offset a, Offset b) =>
+          a.dy < b.dy || (a.dy == b.dy && a.dx < b.dx);
+      // Ö sorts as O: Ökonomie, Party, Zocken.
+      expect(before(oekonomie, party), isTrue);
+      expect(before(party, zocken), isTrue);
+    });
+
+    testWidgets('QUE-05 Kriterium 4: English names and order', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository, locale: const Locale('en'));
+      await openFilterSheet(tester);
+
+      expect(find.text('Dice rolling'), findsOneWidget);
+      expect(find.text('Strategy'), findsOneWidget);
+      final family = tester.getTopLeft(find.text('Family')).dx;
+      final strategy = tester.getTopLeft(find.text('Strategy')).dx;
+      expect(family, lessThan(strategy));
+    });
+
+    testWidgets('a vocabulary error shows a hint with retry, rest works', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)])
+        ..termsFailWith = const CatalogFailure.network();
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      expect(
+        find.text('Die Auswahl konnte nicht geladen werden.'),
+        findsNWidgets(2),
+      );
+      // The other filters still work.
+      await tester.tap(find.byKey(const Key('catalog_filter_players')));
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('2 Spieler').last);
+      await tester.pumpAndSettle();
+      expect(repository.calls.last.query.filters.players, 2);
+
+      repository.termsFailWith = null;
+      await tester.tap(find.byKey(const Key('catalog_terms_retry')).first);
+      await tester.pumpAndSettle();
+      expect(
+        find.byKey(const Key('catalog_term_$genreStrategy')),
+        findsOneWidget,
+      );
+    });
+  });
+
+  group('keyboard', () {
+    Future<void> tab(WidgetTester tester) async {
+      await tester.sendKeyEvent(LogicalKeyboardKey.tab);
+      await tester.pump();
+    }
+
+    bool focusIsIn(Finder finder) {
+      final focused = FocusManager.instance.primaryFocus?.context;
+      return focused != null &&
+          find
+              .descendant(
+                of: finder,
+                matching: find.byElementPredicate((e) => e == focused),
+              )
+              .evaluate()
+              .isNotEmpty;
+    }
+
+    /// The tile's `Focus` sits above its keyed card.
+    bool focusOnTile(String id) {
+      final focused = FocusManager.instance.primaryFocus?.context;
+      return focused != null &&
+          find
+              .ancestor(
+                of: find.byKey(Key('catalog_tile_$id')),
+                matching: find.byElementPredicate((e) => e == focused),
+              )
+              .evaluate()
+              .isNotEmpty;
+    }
+
+    double scrollOffset(WidgetTester tester) => tester
+        .state<ScrollableState>(
+          find.descendant(
+            of: find.byKey(const Key('catalog_result_list')),
+            matching: find.byType(Scrollable),
+          ),
+        )
+        .position
+        .pixels;
+
+    testWidgets(
+      'QUE-06 Kriterium 4: Tab walks field, filters, list (compact)',
+      (tester) async {
+        final repository = FakeCatalogRepository(all: List.generate(75, game));
+        await pumpView(tester, repository);
+
+        await tester.tap(searchInput);
+        await tester.pump();
+        await tab(tester);
+        expect(
+          focusIsIn(find.byKey(const Key('catalog_filter_button'))),
+          isTrue,
+        );
+
+        await tab(tester);
+        expect(focusOnTile('game-0'), isTrue);
+
+        // Walking on scrolls the list (and so loads more).
+        for (var i = 0; i < 12; i++) {
+          await tab(tester);
+        }
+        expect(scrollOffset(tester), greaterThan(0));
+        expect(focusOnTile('game-12'), isTrue);
+      },
+    );
+
+    testWidgets(
+      'QUE-06 Kriterium 4: Tab order is field, filters, list (side bar)',
+      (tester) async {
+        final repository = FakeCatalogRepository(all: List.generate(75, game));
+        await pumpView(tester, repository, width: 1200);
+
+        await tester.tap(searchInput);
+        await tester.pump();
+        await tab(tester);
+        expect(
+          focusIsIn(find.byKey(const Key('catalog_filter_sidebar'))),
+          isTrue,
+          reason: 'the filters come right after the search field',
+        );
+
+        // Through the filters (3 selects, 2 chip groups, reset) to the list.
+        var steps = 0;
+        while (!focusOnTile('game-0') && steps++ < 30) {
+          await tab(tester);
+        }
+        expect(focusOnTile('game-0'), isTrue);
+        expect(steps, lessThan(30));
+      },
+    );
+
+    testWidgets('a selection keeps keyboard focus on the select', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      await tester.tap(find.byKey(const Key('catalog_filter_players')));
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('4 Spieler').last);
+      await tester.pumpAndSettle();
+
+      expect(repository.calls.last.query.filters.players, 4);
+      expect(
+        focusIsIn(find.byKey(const Key('catalog_filter_players'))),
+        isTrue,
+      );
+    });
+
+    testWidgets('the sheet stays open while filters change the URL state', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      await openFilterSheet(tester);
+
+      await tester.tap(find.byKey(const Key('catalog_term_$genreFamily')));
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('catalog_filter_sheet')), findsOneWidget);
+    });
+  });
+
+  group('layout', () {
+    testWidgets('Plattformen Kriterium 2: side bar from 1024 dp', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(tester, repository, width: 1200);
+
+      expect(find.byKey(const Key('catalog_filter_sidebar')), findsOneWidget);
+      expect(find.byKey(const Key('catalog_filter_button')), findsNothing);
+      // The filters work without a sheet.
+      await tester.tap(find.byKey(const Key('catalog_term_$genreFamily')));
+      await tester.pumpAndSettle();
+      expect(repository.calls.last.query.filters.genreIds, {genreFamily});
+    });
+
+    testWidgets('below 1024 dp there is no side bar', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(tester, repository, width: 800);
+
+      expect(find.byKey(const Key('catalog_filter_sidebar')), findsNothing);
+      expect(find.byKey(const Key('catalog_filter_button')), findsOneWidget);
+    });
+
+    for (final width in [420.0, 800.0, 1200.0]) {
+      testWidgets('QUE-06 Kriterium 3: text scale 2.0 at $width dp', (
+        tester,
+      ) async {
+        final repository = FakeCatalogRepository(
+          all: [
+            game(
+              1,
+              title: 'Ein sehr langer Spieltitel für den Test',
+              matchedAltTitle: 'Noch ein langer alternativer Titel',
+            ),
+            game(2, publishers: ['Verlag A', 'Verlag B', 'Verlag C']),
+          ],
+        );
+        await pumpView(tester, repository, width: width, textScale: 2.0);
+
+        expect(tester.takeException(), isNull);
+        if (width < 1024) {
+          await openFilterSheet(tester);
+          expect(tester.takeException(), isNull);
+        }
+      });
+    }
+  });
+
+  group('paging', () {
+    testWidgets(
+      'KAT-01 Kriterium 5: scrolling to the end loads the next page',
+      (tester) async {
+        final repository = FakeCatalogRepository(all: List.generate(75, game));
+        await pumpView(tester, repository);
+        expect(repository.calls, hasLength(1));
+
+        await tester.drag(
+          find.byKey(const Key('catalog_result_list')),
+          const Offset(0, -3000),
+        );
+        await tester.pumpAndSettle();
+
+        expect(repository.calls.length, greaterThanOrEqualTo(2));
+        expect(repository.calls[1].offset, 30);
+        expect(repository.calls[1].query.isEmpty, isTrue);
+      },
+    );
+
+    testWidgets('a first page that does not fill the screen loads on', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: List.generate(75, game));
+      await pumpView(tester, repository);
+      repository.calls.clear();
+
+      // No scroll event can come when everything is visible at once.
+      tester.view.physicalSize = const Size(420, 9000);
+      await tester.pumpAndSettle();
+
+      expect(repository.calls, isNotEmpty);
+      expect(repository.calls.first.offset, 30);
+    });
+
+    testWidgets('the end of the list shows no more button', (tester) async {
+      final repository = FakeCatalogRepository(all: List.generate(5, game));
+
+      await pumpView(tester, repository);
+
+      expect(repository.calls, hasLength(1));
+      expect(find.byKey(const Key('list_footer_load_more')), findsNothing);
+      expect(find.byKey(const Key('list_footer_loading')), findsNothing);
+    });
+
+    testWidgets(
+      'KAT-01 Kriterium 5: a failed load keeps the hits; retry moves focus '
+      'to the first new tile (QUE-06 Kriterium 4)',
+      (tester) async {
+        final repository = FakeCatalogRepository(manual: true);
+        await pumpView(tester, repository, settle: false);
+        await tester.pump();
+        repository.complete(0, items: List.generate(30, game), totalCount: 90);
+        await tester.pump();
+
+        await tester.drag(
+          find.byKey(const Key('catalog_result_list')),
+          const Offset(0, -3000),
+        );
+        await tester.pump();
+        expect(repository.calls, hasLength(2));
+        expect(find.byKey(const Key('list_footer_loading')), findsOneWidget);
+
+        repository.complete(1, failure: const CatalogFailure.network());
+        await tester.pumpAndSettle();
+        await tester.drag(
+          find.byKey(const Key('catalog_result_list')),
+          const Offset(0, -3000),
+        );
+        await tester.pumpAndSettle();
+
+        expect(
+          find.text('Weitere Treffer konnten nicht geladen werden.'),
+          findsOneWidget,
+        );
+        expect(find.byKey(const Key('catalog_tile_game-29')), findsOneWidget);
+        // No automatic retry loop.
+        expect(repository.calls, hasLength(2));
+
+        await tester.tap(find.byKey(const Key('list_footer_retry')));
+        await tester.pump();
+        expect(repository.calls, hasLength(3));
+        expect(repository.calls[2].offset, 30);
+        repository.complete(
+          2,
+          items: List.generate(30, (i) => game(30 + i)),
+          totalCount: 90,
+        );
+        await tester.pumpAndSettle();
+
+        final tile = find.byKey(const Key('catalog_tile_game-30'));
+        expect(tile, findsOneWidget);
+        expect(
+          find.ancestor(
+            of: tile,
+            matching: find.byWidgetPredicate(
+              (w) => w is Focus && (w.focusNode?.hasPrimaryFocus ?? false),
+            ),
+          ),
+          findsOneWidget,
+        );
+      },
+    );
+  });
+}

app/test/features/catalog/presentation/search/catalog_search_controller_test.dart

@@ -0,0 +1,425 @@
+import 'dart:async';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/providers/catalog_providers.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_controller.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_state.dart';
+
+import '../../catalog_test_support.dart';
+
+void main() {
+  late FakeCatalogRepository repository;
+  late ProviderContainer container;
+
+  CatalogSearchController controller() =>
+      container.read(catalogSearchControllerProvider.notifier);
+  CatalogSearchState state() => container.read(catalogSearchControllerProvider);
+
+  /// Wires a fresh container to [repo]; the controller is kept alive.
+  void useRepository(FakeCatalogRepository repo) {
+    repository = repo;
+    container = ProviderContainer.test(
+      overrides: [catalogRepositoryProvider.overrideWithValue(repo)],
+    );
+    container.listen(catalogSearchControllerProvider, (_, _) {});
+  }
+
+  /// Runs [body] with the fake clock of `testWidgets` (`tester.pump` moves
+  /// time, so the debounce `Timer` is testable) and a container wired to a
+  /// fake repository with 75 games.
+  void run(String name, Future<void> Function(WidgetTester tester) body) {
+    testWidgets(name, (tester) async {
+      useRepository(FakeCatalogRepository(all: List.generate(75, game)));
+      await body(tester);
+      await tester.pump();
+    });
+  }
+
+  run('KAT-01 Kriterium 8: init without text and filters shows the catalog', (
+    tester,
+  ) async {
+    expect(state().status, CatalogSearchStatus.loading);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+
+    expect(state().status, CatalogSearchStatus.data);
+    expect(state().items, hasLength(30));
+    expect(state().totalCount, 75);
+    expect(repository.calls.single.offset, 0);
+    expect(repository.calls.single.query.isEmpty, isTrue);
+  });
+
+  run('init uses the start values and runs only once', (tester) async {
+    const initial = CatalogSearchQuery(text: 'catan');
+    controller().init(initial);
+    controller().init(const CatalogSearchQuery(text: 'other'));
+    await tester.pump();
+
+    expect(repository.calls, hasLength(1));
+    expect(state().query.text, 'catan');
+    expect(state().searchedQuery.text, 'catan');
+  });
+
+  run('KAT-01 Kriterium 1: typing searches after the 300 ms debounce', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repository.calls.clear();
+
+    controller().setText('ca');
+    await tester.pump(const Duration(milliseconds: 299));
+    expect(repository.calls, isEmpty);
+
+    controller().setText('cat');
+    await tester.pump(const Duration(milliseconds: 299));
+    expect(repository.calls, isEmpty, reason: 'every keystroke restarts it');
+
+    await tester.pump(const Duration(milliseconds: 1));
+    await tester.pump();
+    expect(repository.calls, hasLength(1));
+    expect(repository.calls.single.query.text, 'cat');
+    expect(repository.calls.single.offset, 0);
+  });
+
+  run('KAT-01 Kriterium 1: Enter searches at once and cancels the debounce', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repository.calls.clear();
+
+    controller()
+      ..setText('catan')
+      ..submitText('catan');
+    await tester.pump();
+    expect(repository.calls, hasLength(1));
+
+    await tester.pump(const Duration(seconds: 1));
+    expect(repository.calls, hasLength(1), reason: 'no second search');
+  });
+
+  run('KAT-01 Kriterium 8: text below 2 characters acts like no text', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery(text: 'catan'));
+    await tester.pump();
+    repository.calls.clear();
+
+    controller().setText('c');
+    await tester.pump(catalogSearchDebounce);
+    await tester.pump();
+
+    expect(repository.calls, hasLength(1));
+    expect(repository.calls.single.query.effective.text, '');
+
+    // Typing a second single-character variant changes nothing effective.
+    controller().setText('d');
+    await tester.pump(catalogSearchDebounce);
+    await tester.pump();
+    expect(repository.calls, hasLength(1));
+  });
+
+  run('KAT-01 Kriterium 1: only the latest request counts', (tester) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    controller().submitText('alpha');
+    await tester.pump();
+    controller().submitText('beta');
+    await tester.pump();
+    expect(repo.calls, hasLength(3));
+
+    // The newest answer comes first, then the stale ones.
+    repo.complete(2, items: [game(3, title: 'Beta')]);
+    await tester.pump();
+    repo.complete(1, items: [game(2, title: 'Alpha')]);
+    repo.complete(0, items: [game(1)]);
+    await tester.pump();
+
+    expect(state().items.map((g) => g.title), ['Beta']);
+    expect(state().searchedQuery.text, 'beta');
+  });
+
+  run('KAT-01 Kriterium 4: changing filters searches at offset 0', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    unawaited(controller().loadMore());
+    await tester.pump();
+    repository.calls.clear();
+
+    controller().setFilters(const CatalogFilters(players: 4));
+    await tester.pump();
+
+    expect(repository.calls.single.offset, 0);
+    expect(repository.calls.single.query.filters.players, 4);
+    expect(state().query.activeFilterCount, 1);
+  });
+
+  run('a pending debounce is executed together with a filter change', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repository.calls.clear();
+
+    controller().setText('catan');
+    controller().setFilters(const CatalogFilters(maxMinutes: 60));
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(repository.calls, hasLength(1));
+    expect(repository.calls.single.query.text, 'catan');
+    expect(repository.calls.single.query.filters.maxMinutes, 60);
+  });
+
+  run('KAT-01 Kriterium 8: clearFilters keeps the text', (tester) async {
+    controller().init(
+      const CatalogSearchQuery(
+        text: 'catan',
+        filters: CatalogFilters(players: 2),
+      ),
+    );
+    await tester.pump();
+
+    controller().clearFilters();
+    await tester.pump();
+
+    expect(state().query.text, 'catan');
+    expect(state().query.hasFilters, isFalse);
+  });
+
+  run('KAT-01 Kriterium 5: loadMore appends the next page', (tester) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+
+    unawaited(controller().loadMore());
+    await tester.pump();
+
+    expect(state().items, hasLength(60));
+    expect(repository.calls.last.offset, 30);
+    expect(state().hasMore, isTrue);
+
+    unawaited(controller().loadMore());
+    await tester.pump();
+    expect(state().items, hasLength(75));
+    expect(state().hasMore, isFalse);
+
+    // Nothing more to load.
+    unawaited(controller().loadMore());
+    await tester.pump();
+    expect(repository.calls, hasLength(3));
+  });
+
+  run('KAT-01 Kriterium 5: loadMore does not run twice at the same time', (
+    tester,
+  ) async {
+    final repo = FakeCatalogRepository(
+      all: List.generate(75, game),
+      manual: true,
+    );
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: repo.all.sublist(0, 30), totalCount: 75);
+    await tester.pump();
+
+    unawaited(controller().loadMore());
+    unawaited(controller().loadMore());
+    await tester.pump();
+
+    expect(repo.calls, hasLength(2));
+    expect(state().loadingMore, isTrue);
+  });
+
+  run('KAT-01 Kriterium 5: duplicate IDs of a later page are dropped', (
+    tester,
+  ) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: [game(1), game(2)], totalCount: 4);
+    await tester.pump();
+
+    unawaited(controller().loadMore());
+    await tester.pump();
+    repo.complete(1, items: [game(2), game(3)], totalCount: 4);
+    await tester.pump();
+
+    expect(state().items.map((g) => g.id), ['game-1', 'game-2', 'game-3']);
+  });
+
+  run('a page without new items ends the list (no endless loading)', (
+    tester,
+  ) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: [game(1), game(2)], totalCount: 5);
+    await tester.pump();
+
+    unawaited(controller().loadMore());
+    await tester.pump();
+    repo.complete(1, items: const [], totalCount: 0);
+    await tester.pump();
+
+    expect(state().items, hasLength(2));
+    expect(state().hasMore, isFalse);
+    expect(state().loadingMore, isFalse);
+  });
+
+  run('a new search discards a running loadMore', (tester) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: [game(1)], totalCount: 3);
+    await tester.pump();
+    unawaited(controller().loadMore());
+    await tester.pump();
+
+    controller().submitText('neu');
+    await tester.pump();
+    repo.complete(1, items: [game(2), game(3)], totalCount: 3);
+    repo.complete(2, items: [game(9, title: 'Neu')], totalCount: 1);
+    await tester.pump();
+
+    expect(state().items.map((g) => g.title), ['Neu']);
+    expect(state().loadingMore, isFalse);
+  });
+
+  run('KAT-01 Kriterium 5: a stale loadMore answer is not appended', (
+    tester,
+  ) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: [game(1)], totalCount: 3);
+    await tester.pump();
+    unawaited(controller().loadMore());
+    await tester.pump();
+
+    // A new search starts while the next page is still on its way ...
+    controller().submitText('neu');
+    await tester.pump();
+    // ... and the old page arrives before the new answer.
+    repo.complete(1, items: [game(2), game(3)], totalCount: 3);
+    await tester.pump();
+    expect(state().items.map((g) => g.id), ['game-1']);
+
+    repo.complete(2, items: [game(9, title: 'Neu')], totalCount: 1);
+    await tester.pump();
+    expect(state().items.map((g) => g.title), ['Neu']);
+  });
+
+  run('KAT-01 Kriterium 5: an error while loading more keeps the hits', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+
+    repository.failWith = const CatalogFailure.network();
+    unawaited(controller().loadMore());
+    await tester.pump();
+
+    expect(state().items, hasLength(30));
+    expect(state().status, CatalogSearchStatus.data);
+    expect(state().loadMoreFailure, isA<CatalogNetworkFailure>());
+    expect(state().loadingMore, isFalse);
+
+    repository.failWith = null;
+    unawaited(controller().retry());
+    await tester.pump();
+
+    expect(state().items, hasLength(60));
+    expect(state().loadMoreFailure, isNull);
+  });
+
+  run('Zustände Kriterium 3: an error keeps text and filters, retry works', (
+    tester,
+  ) async {
+    repository.failWith = const CatalogFailure.network();
+    controller().init(
+      const CatalogSearchQuery(
+        text: 'catan',
+        filters: CatalogFilters(players: 3),
+      ),
+    );
+    await tester.pump();
+
+    expect(state().status, CatalogSearchStatus.error);
+    expect(state().failure, isA<CatalogNetworkFailure>());
+    expect(state().query.text, 'catan');
+    expect(state().query.filters.players, 3);
+
+    repository.failWith = null;
+    unawaited(controller().retry());
+    await tester.pump();
+
+    expect(state().status, CatalogSearchStatus.data);
+    expect(state().failure, isNull);
+    expect(repository.calls.last.query.text, 'catan');
+  });
+
+  run('Zustände Kriterium 1: no hits give the empty status', (tester) async {
+    final repo = FakeCatalogRepository();
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery(text: 'zzz'));
+    await tester.pump();
+
+    expect(state().status, CatalogSearchStatus.empty);
+    expect(state().searchedQuery.text, 'zzz');
+  });
+
+  run('a new search keeps the old hits visible while it runs', (tester) async {
+    final repo = FakeCatalogRepository(manual: true);
+    useRepository(repo);
+
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    repo.complete(0, items: [game(1)], totalCount: 1);
+    await tester.pump();
+
+    controller().submitText('neu');
+    await tester.pump();
+
+    expect(state().refreshing, isTrue);
+    expect(state().status, CatalogSearchStatus.data);
+    expect(state().items, hasLength(1));
+    // The shown results still belong to the old query.
+    expect(state().searchedQuery.text, '');
+    expect(state().query.text, 'neu');
+  });
+
+  run('searchGeneration counts completed first-page searches only', (
+    tester,
+  ) async {
+    controller().init(const CatalogSearchQuery());
+    await tester.pump();
+    expect(state().searchGeneration, 1);
+
+    unawaited(controller().loadMore());
+    await tester.pump();
+    expect(state().searchGeneration, 1);
+
+    controller().submitText('abc');
+    await tester.pump();
+    expect(state().searchGeneration, 2);
+  });
+}

app/test/features/catalog/presentation/search/catalog_search_screen_test.dart

@@ -0,0 +1,320 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:go_router/go_router.dart';
+import 'package:shuffle/core/routing/app_router.dart';
+import 'package:shuffle/core/routing/url_replacer.dart';
+import 'package:shuffle/features/auth/domain/auth_status.dart';
+import 'package:shuffle/features/auth/domain/auth_user.dart';
+import 'package:shuffle/features/auth/presentation/providers/auth_redirect.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/presentation/catalog_routes.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_view.dart';
+
+import '../../../../helpers/pump_app.dart';
+import '../../../../helpers/router_helpers.dart';
+import '../../catalog_test_support.dart';
+import 'catalog_search_test_support.dart';
+
+void main() {
+  group('route /catalog', () {
+    testWidgets('Plattformen: /catalog is public (no sign-in redirect)', (
+      tester,
+    ) async {
+      expect(
+        authRedirectFor(
+          const SignedOut(),
+          Uri.parse('/catalog?q=catan'),
+          privatePaths: const [],
+        ),
+        isNull,
+      );
+      expect(
+        authRedirectFor(
+          const SignedIn(
+            AuthUser(id: 'u1', email: 'a@example.com', emailConfirmed: true),
+          ),
+          Uri.parse('/catalog'),
+        ),
+        isNull,
+      );
+    });
+
+    testWidgets('KAT-01 Kriterium 1: the URL parameters are the start values', (
+      tester,
+    ) async {
+      useWindow(tester, 420);
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final container = await pumpShuffleApp(
+        tester,
+        overrides: catalogOverrides(repository),
+      );
+
+      container
+          .read(appRouterProvider)
+          .go('/catalog?q=catan&players=3&maxMinutes=60&genre=$genreStrategy');
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('catalog_search_screen')), findsOneWidget);
+      final query = repository.calls.first.query;
+      expect(query.text, 'catan');
+      expect(query.filters.players, 3);
+      expect(query.filters.maxMinutes, 60);
+      expect(query.filters.genreIds, {genreStrategy});
+    });
+
+    testWidgets('invalid URL parameters are ignored, the page still opens', (
+      tester,
+    ) async {
+      useWindow(tester, 420);
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final container = await pumpShuffleApp(
+        tester,
+        overrides: catalogOverrides(repository),
+      );
+
+      container
+          .read(appRouterProvider)
+          .go('/catalog?players=99&genre=xyz&maxMinutes=abc');
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('catalog_search_screen')), findsOneWidget);
+      expect(repository.calls.first.query.isEmpty, isTrue);
+    });
+
+    testWidgets('Android: system back from a deep link returns to the start '
+        'page instead of closing the app', (tester) async {
+      useWindow(tester, 420);
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final container = await pumpShuffleApp(
+        tester,
+        overrides: catalogOverrides(repository),
+      );
+      container.read(appRouterProvider).go('/catalog?q=catan');
+      await tester.pumpAndSettle();
+      expect(find.byKey(const Key('catalog_search_screen')), findsOneWidget);
+
+      // The framework's system back; `false` would mean the app closes.
+      final handled = await tester.binding.handlePopRoute();
+      await tester.pumpAndSettle();
+
+      expect(handled, isTrue);
+      expect(find.byKey(const Key('home_screen')), findsOneWidget);
+    });
+
+    testWidgets('start page entry opens the search and back returns', (
+      tester,
+    ) async {
+      useWindow(tester, 420);
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpShuffleApp(tester, overrides: catalogOverrides(repository));
+
+      expect(find.text('Search games'), findsOneWidget);
+      expect(
+        tester
+            .getSize(find.byKey(const Key('home_catalog_search_button')))
+            .height,
+        greaterThanOrEqualTo(48),
+      );
+      await tester.tap(find.byKey(const Key('home_catalog_search_button')));
+      await tester.pumpAndSettle();
+      expect(find.byKey(const Key('catalog_search_screen')), findsOneWidget);
+      expect(find.text('Spiel 1'), findsOneWidget);
+
+      await tester.tap(find.byType(BackButton));
+      await tester.pumpAndSettle();
+      expect(find.byKey(const Key('home_screen')), findsOneWidget);
+    });
+  });
+
+  group('URL sync (web)', () {
+    late List<MethodCall> platformCalls;
+
+    setUp(() => platformCalls = []);
+
+    Future<GoRouter> pumpRouted(
+      WidgetTester tester,
+      FakeCatalogRepository repository, {
+      required bool isWeb,
+      String initialLocation = '/catalog?q=alt',
+    }) async {
+      useWindow(tester, 420);
+      tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
+        SystemChannels.navigation,
+        (call) async {
+          platformCalls.add(call);
+          return null;
+        },
+      );
+      addTearDown(
+        () => tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
+          SystemChannels.navigation,
+          null,
+        ),
+      );
+      final router = buildTestRouter(
+        routes: [
+          GoRoute(
+            path: '/',
+            builder: (context, state) => const SizedBox(),
+            routes: catalogRoutes,
+          ),
+        ],
+        initialLocation: initialLocation,
+      );
+      addTearDown(router.dispose);
+      await pumpApp(
+        tester,
+        router: router,
+        overrides: [
+          ...catalogOverrides(repository),
+          urlReplacerProvider.overrideWithValue(UrlReplacer(isWeb: isWeb)),
+        ],
+        settle: false,
+      );
+      await tester.pumpAndSettle();
+      platformCalls.clear();
+      return router;
+    }
+
+    testWidgets('URL is replaced after a search without rebuilding the page', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final router = await pumpRouted(tester, repository, isWeb: true);
+      final stateBefore = tester.state(find.byType(CatalogSearchView));
+      final callsBefore = repository.calls.length;
+
+      await tester.enterText(searchInput, 'catan');
+      await tester.testTextInput.receiveAction(TextInputAction.search);
+      await tester.pumpAndSettle();
+
+      // Router and browser address agree on the new search.
+      expect(currentUri(router).queryParameters['q'], 'catan');
+      final updates = platformCalls.where(
+        (c) => c.method == 'routeInformationUpdated',
+      );
+      expect(updates, isNotEmpty);
+      final last = updates.last.arguments as Map<Object?, Object?>;
+      expect(last['uri'].toString(), '/catalog?q=catan');
+      expect(last['replace'], isTrue);
+      // No history entry from the router for this change.
+      expect(
+        updates.where((c) => (c.arguments as Map)['replace'] != true),
+        isEmpty,
+      );
+      // Same page state: nothing rebuilt, field and focus intact.
+      expect(tester.state(find.byType(CatalogSearchView)), same(stateBefore));
+      expect(tester.widget<TextField>(searchInput).controller!.text, 'catan');
+      // Exactly one more search (no re-init after the URL change).
+      expect(repository.calls.length, callsBefore + 1);
+    });
+
+    testWidgets('filters are part of the written URL', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final router = await pumpRouted(tester, repository, isWeb: true);
+      await tester.tap(find.byKey(const Key('catalog_filter_button')));
+      await tester.pumpAndSettle();
+
+      await tester.tap(find.byKey(const Key('catalog_term_$genreFamily')));
+      await tester.pumpAndSettle();
+
+      final params = currentUri(router).queryParameters;
+      expect(params['q'], 'alt');
+      expect(params['genre'], genreFamily);
+      // Writing the URL does not close the open filter sheet.
+      expect(find.byKey(const Key('catalog_filter_sheet')), findsOneWidget);
+    });
+
+    const unknownGenre = '99999999-9999-4999-8999-999999999999';
+    const unknownMechanic = '88888888-8888-4888-8888-888888888888';
+
+    testWidgets('unknown IDs from the URL are removed once the vocabulary is '
+        'loaded; valid ones stay, the search runs once more', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final router = await pumpRouted(
+        tester,
+        repository,
+        isWeb: true,
+        initialLocation:
+            '/catalog?genre=$genreStrategy,$unknownGenre'
+            '&mechanic=$unknownMechanic,$mechanicDice',
+      );
+
+      final last = repository.calls.last.query.filters;
+      expect(last.genreIds, {genreStrategy});
+      expect(last.mechanicIds, {mechanicDice});
+      // First search with the raw URL values, then the cleaned one(s); no loop.
+      expect(repository.calls.length, lessThanOrEqualTo(3));
+      final before = repository.calls.length;
+      await tester.pump(const Duration(seconds: 2));
+      expect(repository.calls.length, before);
+      // The counter shows what is really active and the URL follows.
+      expect(find.text('Filter (2)'), findsOneWidget);
+      final params = currentUri(router).queryParameters;
+      expect(params['genre'], genreStrategy);
+      expect(params['mechanic'], mechanicDice);
+    });
+
+    testWidgets('a single unknown ID triggers exactly one extra search', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpRouted(
+        tester,
+        repository,
+        isWeb: true,
+        initialLocation: '/catalog?genre=$genreStrategy,$unknownGenre',
+      );
+
+      expect(repository.calls, hasLength(2));
+      expect(repository.calls.last.query.filters.genreIds, {genreStrategy});
+    });
+
+    testWidgets('only known IDs: nothing is removed, no extra search', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpRouted(
+        tester,
+        repository,
+        isWeb: true,
+        initialLocation: '/catalog?genre=$genreStrategy',
+      );
+
+      expect(repository.calls, hasLength(1));
+    });
+
+    testWidgets('a vocabulary load error removes nothing', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)])
+        ..termsFailWith = const CatalogFailure.network();
+      await pumpRouted(
+        tester,
+        repository,
+        isWeb: true,
+        initialLocation: '/catalog?genre=$genreStrategy,$unknownGenre',
+      );
+
+      expect(repository.calls, hasLength(1));
+      expect(repository.calls.last.query.filters.genreIds, {
+        genreStrategy,
+        unknownGenre,
+      });
+    });
+
+    testWidgets('outside the web nothing is written', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final router = await pumpRouted(tester, repository, isWeb: false);
+
+      await tester.enterText(searchInput, 'catan');
+      await tester.testTextInput.receiveAction(TextInputAction.search);
+      await tester.pumpAndSettle();
+
+      expect(
+        platformCalls.where((c) => c.method == 'routeInformationUpdated'),
+        isEmpty,
+      );
+      expect(currentUri(router).queryParameters['q'], 'alt');
+    });
+  });
+}

app/test/features/catalog/presentation/search/catalog_search_test_support.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_view.dart';
+
+import '../../../../helpers/pump_app.dart';
+import '../../catalog_test_support.dart';
+
+/// Sets a logical window size for the test (device pixel ratio 1).
+void useWindow(WidgetTester tester, double width, [double height = 900]) {
+  tester.view.physicalSize = Size(width, height);
+  tester.view.devicePixelRatio = 1;
+  addTearDown(tester.view.reset);
+}
+
+Future<void> pumpView(
+  WidgetTester tester,
+  FakeCatalogRepository repository, {
+  CatalogSearchQuery initialQuery = const CatalogSearchQuery(),
+  ValueChanged<String>? onReportGame,
+  Locale locale = const Locale('de'),
+  double? textScale,
+  double width = 420,
+  bool settle = true,
+}) async {
+  useWindow(tester, width);
+  await pumpApp(
+    tester,
+    locale: locale,
+    textScale: textScale,
+    overrides: catalogOverrides(repository),
+    settle: false,
+    home: Scaffold(
+      body: CatalogSearchView(
+        initialQuery: initialQuery,
+        onReportGame: onReportGame,
+      ),
+    ),
+  );
+  if (settle) {
+    await tester.pumpAndSettle();
+  }
+}
+
+Finder get searchInput => find.descendant(
+  of: find.byKey(const Key('catalog_search_field')),
+  matching: find.byType(TextField),
+);

app/test/features/catalog/presentation/search/catalog_search_view_test.dart

@@ -0,0 +1,394 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shuffle/core/widgets/game_cover.dart';
+import 'package:shuffle/features/catalog/domain/catalog_failure.dart';
+import 'package:shuffle/features/catalog/domain/catalog_search_query.dart';
+import 'package:shuffle/features/catalog/presentation/search/catalog_search_controller.dart';
+
+import '../../catalog_test_support.dart';
+import 'catalog_search_test_support.dart';
+
+void main() {
+  group('list and tiles', () {
+    testWidgets('KAT-01 Kriterium 8: starts with the whole catalog', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: List.generate(75, game));
+
+      await pumpView(tester, repository);
+
+      expect(find.byKey(const Key('catalog_tile_game-0')), findsOneWidget);
+      expect(find.text('75 Spiele'), findsOneWidget);
+      expect(repository.calls.single.query.isEmpty, isTrue);
+    });
+
+    testWidgets('KAT-01 Kriterium 1: tile shows facts, year and publisher', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(
+        all: [game(1, title: 'Catan', minPlayers: 3, maxPlayers: 4)],
+      );
+
+      await pumpView(tester, repository);
+
+      expect(find.text('Catan'), findsOneWidget);
+      expect(find.text('1995 · Kosmos'), findsOneWidget);
+      expect(find.text('3–4 Spieler · 60–120 Min. · ab 10'), findsOneWidget);
+      expect(find.text('1 Spiel'), findsOneWidget);
+    });
+
+    testWidgets('KAT-01 Kriterium 3: two publishers shown, more as +n', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(
+        all: [
+          game(1, publishers: ['A', 'B', 'C', 'D']),
+        ],
+      );
+
+      await pumpView(tester, repository);
+
+      expect(find.text('1995 · A, B +2'), findsOneWidget);
+    });
+
+    testWidgets('KAT-01 Kriterium 1: missing facts are left out', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(
+        all: [
+          game(
+            1,
+            year: null,
+            minPlayers: 2,
+            maxPlayers: 2,
+            minMinutes: null,
+            maxMinutes: 30,
+            minAge: null,
+            publishers: const [],
+          ),
+        ],
+      );
+
+      await pumpView(tester, repository);
+
+      expect(find.text('2 Spieler · 30 Min.'), findsOneWidget);
+      expect(find.textContaining('ab '), findsNothing);
+      expect(find.textContaining('·  '), findsNothing);
+    });
+
+    testWidgets('KAT-01 Kriterium 2: shows the matched alternative title', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(
+        all: [
+          game(1, title: 'Catan', matchedAltTitle: 'Die Siedler von Catan'),
+        ],
+      );
+
+      await pumpView(tester, repository);
+
+      expect(find.text('auch: Die Siedler von Catan'), findsOneWidget);
+    });
+
+    testWidgets('KAT-05 Kriterium 10: tile shows the cover placeholder', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(tester, repository);
+
+      final cover = tester.widget<GameCover>(find.byType(GameCover));
+      expect(cover.imageUrl, isNull);
+      expect(cover.titleVisibleNearby, isTrue);
+      expect(find.byKey(const Key('game_cover_placeholder')), findsOneWidget);
+    });
+
+    testWidgets('a tile without onTap is not a button', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      final handle = tester.ensureSemantics();
+
+      await pumpView(tester, repository);
+
+      final node = tester.getSemantics(
+        find.byKey(const Key('catalog_tile_game-1')),
+      );
+      expect(node.label, contains('Spiel 1'));
+      expect(node.flagsCollection.isButton, isFalse);
+      handle.dispose();
+    });
+
+    testWidgets('QUE-05 Kriterium 3: English texts and plural', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(tester, repository, locale: const Locale('en'));
+
+      expect(find.text('1 game'), findsOneWidget);
+      expect(find.text('3–4 players · 60–120 min · ages 10+'), findsOneWidget);
+      expect(find.text('Search games'), findsWidgets);
+    });
+  });
+
+  group('search field', () {
+    testWidgets('KAT-01 Kriterium 1: typing searches after the debounce', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      repository.calls.clear();
+
+      await tester.enterText(searchInput, 'catan');
+      await tester.pump(const Duration(milliseconds: 200));
+      expect(repository.calls, isEmpty);
+      await tester.pump(const Duration(milliseconds: 150));
+
+      expect(repository.calls.single.query.text, 'catan');
+    });
+
+    testWidgets('KAT-01 Kriterium 1: Enter searches without waiting', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(tester, repository);
+      repository.calls.clear();
+
+      await tester.enterText(searchInput, 'catan');
+      await tester.testTextInput.receiveAction(TextInputAction.search);
+      await tester.pump();
+
+      expect(repository.calls.single.query.text, 'catan');
+    });
+
+    testWidgets('clear button empties the field and searches at once', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'catan'),
+      );
+      expect(find.byKey(const Key('catalog_search_clear')), findsOneWidget);
+      repository.calls.clear();
+
+      await tester.tap(find.byKey(const Key('catalog_search_clear')));
+      await tester.pump();
+
+      expect(repository.calls.single.query.text, '');
+      expect(find.byKey(const Key('catalog_search_clear')), findsNothing);
+      expect(tester.widget<TextField>(searchInput).controller!.text, '');
+    });
+
+    testWidgets('the field starts with the text from the URL', (tester) async {
+      final repository = FakeCatalogRepository(all: [game(1)]);
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'catan'),
+      );
+
+      expect(tester.widget<TextField>(searchInput).controller!.text, 'catan');
+      expect(repository.calls.first.query.text, 'catan');
+    });
+
+    testWidgets('Eingabegrenzen: the field accepts at most 100 characters', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository();
+      await pumpView(tester, repository);
+
+      await tester.enterText(searchInput, 'a' * 130);
+      await tester.pump(catalogSearchDebounce);
+
+      expect(
+        tester.widget<TextField>(searchInput).controller!.text,
+        hasLength(100),
+      );
+      expect(repository.calls.last.query.text, hasLength(100));
+    });
+
+    testWidgets('autofocus follows the parameter (web only by default)', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository();
+      await pumpView(tester, repository);
+
+      expect(tester.widget<TextField>(searchInput).autofocus, isFalse);
+    });
+  });
+
+  group('states', () {
+    testWidgets('Zustände Kriterium 1: loading shows an indicator', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(manual: true);
+
+      await pumpView(tester, repository, settle: false);
+      await tester.pump();
+
+      expect(find.byKey(const Key('catalog_loading')), findsOneWidget);
+      // Search field and filter button stay usable.
+      expect(searchInput, findsOneWidget);
+      expect(find.byKey(const Key('catalog_filter_button')), findsOneWidget);
+    });
+
+    testWidgets('a new search keeps the old hits and shows a thin bar', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(manual: true);
+      await pumpView(tester, repository, settle: false);
+      await tester.pump();
+      repository.complete(0, items: [game(1)]);
+      await tester.pump();
+
+      await tester.enterText(searchInput, 'neu');
+      await tester.testTextInput.receiveAction(TextInputAction.search);
+      await tester.pump();
+
+      expect(find.text('Spiel 1'), findsOneWidget);
+      expect(find.byKey(const Key('catalog_refreshing')), findsOneWidget);
+    });
+
+    testWidgets('KAT-01 Kriterium 6: no hits for a text give the hint', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository();
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'zzz'),
+      );
+
+      expect(find.text('Keine Spiele zu „zzz“ gefunden.'), findsOneWidget);
+      expect(
+        find.text('Prüfe die Schreibweise oder entferne Filter.'),
+        findsOneWidget,
+      );
+      // #3 passes no callback: no report action, no reset without filters.
+      expect(find.byKey(const Key('catalog_empty_report')), findsNothing);
+      expect(find.byKey(const Key('catalog_empty_reset')), findsNothing);
+    });
+
+    testWidgets('KAT-01 Kriterium 6: onReportGame adds the action', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository();
+      String? reported;
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'zzz'),
+        onReportGame: (text) => reported = text,
+      );
+      await tester.tap(find.byKey(const Key('catalog_empty_report')));
+
+      expect(reported, 'zzz');
+      expect(find.text('Fehlendes Spiel melden'), findsOneWidget);
+    });
+
+    testWidgets('KAT-01 Kriterium 6: reset is offered with active filters', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository();
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(
+          text: 'zzz',
+          filters: CatalogFilters(players: 3),
+        ),
+      );
+      repository.calls.clear();
+      repository.all = [game(1)];
+      await tester.tap(find.byKey(const Key('catalog_empty_reset')));
+      await tester.pumpAndSettle();
+
+      expect(repository.calls.single.query.text, 'zzz');
+      expect(repository.calls.single.query.hasFilters, isFalse);
+    });
+
+    testWidgets('KAT-01 Kriterium 8: no hits for filters only', (tester) async {
+      final repository = FakeCatalogRepository();
+
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(
+          filters: CatalogFilters(players: 3),
+        ),
+      );
+
+      expect(
+        find.text('Keine Spiele passen zu deinen Filtern.'),
+        findsOneWidget,
+      );
+      expect(find.byKey(const Key('catalog_empty_reset')), findsOneWidget);
+      expect(find.byKey(const Key('catalog_empty_report')), findsNothing);
+    });
+
+    testWidgets('an empty catalog says so', (tester) async {
+      final repository = FakeCatalogRepository();
+
+      await pumpView(tester, repository);
+
+      expect(find.text('Der Katalog ist noch leer.'), findsOneWidget);
+    });
+
+    testWidgets('Zustände Kriterium 3: offline shows the hint and retries', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository(all: [game(1)])
+        ..failWith = const CatalogFailure.network();
+      await pumpView(
+        tester,
+        repository,
+        initialQuery: const CatalogSearchQuery(text: 'catan'),
+      );
+      expect(
+        find.text('Keine Verbindung. Für die Suche brauchst du Internet.'),
+        findsOneWidget,
+      );
+      // Text and filters survive the error.
+      expect(tester.widget<TextField>(searchInput).controller!.text, 'catan');
+
+      repository.failWith = null;
+      await tester.tap(find.byKey(const Key('catalog_error_retry')));
+      await tester.pumpAndSettle();
+
+      expect(find.text('Spiel 1'), findsOneWidget);
+      expect(find.byKey(const Key('catalog_error')), findsNothing);
+    });
+
+    testWidgets('rejected input shows an own text and offers no retry', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository()
+        ..failWith = const CatalogFailure.invalidInput();
+
+      await pumpView(tester, repository);
+
+      expect(
+        find.text(
+          'Diese Suche wird nicht unterstützt. Ändere den Suchbegriff oder die Filter.',
+        ),
+        findsOneWidget,
+      );
+      expect(find.byKey(const Key('catalog_error_retry')), findsNothing);
+    });
+
+    testWidgets('Zustände Kriterium 2: other errors show the generic text', (
+      tester,
+    ) async {
+      final repository = FakeCatalogRepository()
+        ..failWith = const CatalogFailure.unexpected();
+
+      await pumpView(tester, repository);
+
+      expect(find.text('Die Suche ist gerade nicht möglich.'), findsOneWidget);
+      expect(find.byKey(const Key('catalog_error_retry')), findsOneWidget);
+    });
+  });
+}

docs/design-system.md

@@ -79,4 +79,22 @@ getestet; Tests liegen in `app/test/core/widgets/` und dienen als lauffähige Vo
 | `AppBanner` | `type` (`AppBannerType.info` / `error`), `message`, `typeLabel` (gesprochenes Präfix, z. B. „Fehler“), optional `actionLabel` + `onAction` (48-dp-TextButton), `actionEnabled` (Standard `true`; `false` lässt die Aktion sichtbar, aber deaktiviert, z. B. während eine Anfrage läuft; Semantics melden sie als nicht aktiviert, der Screenreader-Fokus geht nicht verloren). Live-Region mit „typeLabel: message“. |
 | `AppFieldError` | Interner Baustein: Fehlerzeile mit Icon als Live-Region, von Textfeld und Checkbox genutzt. |
 
+## Listen-Komponenten (`app/lib/core/widgets/`, #3 KAT-01)
+
+Für jede Liste in R1 (Zustände Krit. 1–3): Leer- und Fehlerzustand sowie Listenfuß zum Nachladen. Gleiche Regeln wie bei den
+Formular-Komponenten (Texte von außen, Tests gegen die Guidelines in Hell und Dunkel, Umbruch statt Abschneiden bei 200 %).
+
+| Komponente | Zweck und API (Kurzform) |
+|---|---|
+| `AppStateMessage` | Leer-/Fehlerzustand: `icon` (dekorativ, für Screenreader ausgeblendet), `title`, optional `message`, `actions` (`AppStateAction(label, onPressed, key)`; die erste Aktion ist tonal hervorgehoben, weitere umrandet; alle 48 dp). Titel und Hinweis sind eine Live-Region. |
+| `AppListFooter` | Fuß einer seitenweise geladenen Liste: `isLoading` (beschrifteter Fortschrittskreis), `hasMore` (Schaltfläche „Weitere laden“, per Tastatur und Screenreader erreichbar), `errorMessage` + Wiederholen (bereits geladene Einträge bleiben). Vorrang: Fehler vor Laden vor „Weitere laden“. Automatisches Nachladen ist Sache des Aufrufers; die Schaltfläche bleibt der Weg für Tastatur und Screenreader. |
+
+**Katalogsuche (`features/catalog/presentation/search/`)** – Aufbau und Verhalten, Entscheidungen der Umsetzung (Spec #3 § 5.6):
+
+- Kompakt (< 600 dp) und mittel (600–1023 dp): Suchfeld, darunter die Schaltfläche „Filter (n)“ mit Bottom Sheet (Änderungen wirken sofort, „Fertig“ schließt); ab 1024 dp feste Seitenleiste (320 dp) links, Trefferliste rechts mit höchstens 720 dp Breite.
+- Einfachauswahl (Spielerzahl, Dauer, Alter) als beschriftete Auswahlfelder mit „Beliebig“; Genre und Mechanik als Filter-Chips, nach lokalisiertem Namen sortiert. Fehler beim Laden der Begriffe betrifft nur diese beiden Bereiche („Erneut versuchen“).
+- Trefferkachel: `GameCover` klein (Platzhalter), Titel (2 Zeilen), „auch: …“, Jahr · Verlage (zwei, sonst „+n“), Kurzangaben; ein zusammengefasstes Semantics-Label. Ohne `onTap` ist die Kachel kein Button, aber ein Tab-Stopp mit Fokusring (3 dp): Tastaturnutzer durchlaufen so die Liste, was sie scrollt und das Nachladen auslöst (die Liste wird lazy gebaut). Im Screenreader-Durchgang bewerten, ob die vielen Tab-Stopps stören.
+- Trefferzahl über der Liste; Ansage der Trefferzahl 600 ms nach Abschluss der letzten Suche (`SemanticsService.sendAnnouncement`), nie während des Tippens.
+- Nach „Weitere laden“ (bzw. „Erneut versuchen“ im Listenfuß) springt der Fokus auf die erste neu geladene Kachel. Automatisches Nachladen, wenn weniger als etwa fünf Kacheln unterhalb des sichtbaren Bereichs liegen; nach einem Fehler nur noch über die Schaltfläche (keine Wiederholungsschleife).
+
 Auth-Screens: Layout-Skizzen und Textvorschläge siehe `docs/design/auth-screens.md`.