hardened API decoding against server fields the models did not expect

The Talk room list crashed for a new account because the server omits
lastMessage for rooms without a visible message and the model required it.
Beyond that single field, a review of the Talk models against the OpenAPI
spec of the installed version (23.0.8) found the same crash class in several
places: closed enums over open server values (inCall bitmask, rich-object
types, actor and message types), a deleted parent sent as {id, deleted},
and the autocomplete status arriving as an object.

- json_serializable `checked: true`: decode errors now name class and field
- lists (rooms, messages, participants, autocomplete) decode per entry;
  a malformed entry is skipped and reported via ClientErrorReporter
- unknownEnumValue fallbacks for all response enums of Talk and breakers
- lastMessage nullable; inCall as bitmask; deleted parent placeholder;
  autocomplete status object/string; fixed shareWithDisplayNameUnique key
- GetRoomParams no longer sends null query parameters

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HrepDTL4qDe35TuS29sLW3

test/api/autocomplete_response_test.dart

@@ -0,0 +1,32 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/api/json_lenient.dart';
+import 'package:marianum_mobile/api/marianumcloud/autocomplete/autocomplete_response.dart';
+
+void main() {
+  test('accepts the status as object, string or empty', () {
+    final response = AutocompleteResponse.fromJson({
+      'data': [
+        {
+          'id': 'a',
+          'label': 'A',
+          'status': {'status': 'online', 'message': null},
+        },
+        {'id': 'b', 'label': 'B', 'status': ''},
+        {'id': 'c', 'label': 'C', 'status': 'dnd'},
+      ],
+    });
+    expect(response.data.map((e) => e.status), ['online', null, 'dnd']);
+    expect(drainDecodeWarnings(), isEmpty);
+  });
+
+  test('skips an entry without id instead of failing the search', () {
+    final response = AutocompleteResponse.fromJson({
+      'data': [
+        {'label': 'no id'},
+        {'id': 'b', 'label': 'B'},
+      ],
+    });
+    expect(response.data.single.id, 'b');
+    expect(drainDecodeWarnings().single, contains('"id"'));
+  });
+}

test/talk/get_participants_response_test.dart

@@ -0,0 +1,23 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/api/marianumcloud/talk/get_participants/get_participants_response.dart';
+
+void main() {
+  test('reads inCall as a bitmask', () {
+    final participant = GetParticipantsResponseObject.fromJson({
+      'attendeeId': 1,
+      'actorType': 'users',
+      'actorId': 'u',
+      'displayName': 'U',
+      'participantType': 3,
+      'lastPing': 0,
+      'inCall': 7,
+      'permissions': 0,
+      'attendeePermissions': 0,
+      'sessionIds': <String>[],
+    });
+    expect(participant.isInCall, isTrue);
+    expect(participant.inCallWithAudio, isTrue);
+    expect(participant.inCallWithVideo, isTrue);
+    expect(participant.inCallViaPhone, isFalse);
+  });
+}

test/talk/get_room_response_test.dart

@@ -0,0 +1,122 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/api/json_lenient.dart';
+import 'package:marianum_mobile/api/marianumcloud/talk/chat/get_chat_response.dart';
+import 'package:marianum_mobile/api/marianumcloud/talk/room/get_room_response.dart';
+
+Map<String, dynamic> _room({bool withLastMessage = true}) => {
+  'id': 1,
+  'token': 'abc',
+  'type': 2,
+  'name': 'room',
+  'displayName': 'Room',
+  'description': '',
+  'participantType': 3,
+  'participantFlags': 0,
+  'readOnly': 0,
+  'listable': 0,
+  'lastPing': 0,
+  'sessionId': '0',
+  'hasPassword': false,
+  'hasCall': false,
+  'callFlag': 0,
+  'canStartCall': true,
+  'canDeleteConversation': false,
+  'canLeaveConversation': true,
+  'lastActivity': 1700000000,
+  'isFavorite': false,
+  'notificationLevel': 0,
+  'unreadMessages': 0,
+  'unreadMention': false,
+  'unreadMentionDirect': false,
+  'lastReadMessage': 0,
+  'lastCommonReadMessage': 0,
+  if (withLastMessage)
+    'lastMessage': {
+      'id': 7,
+      'token': 'abc',
+      'actorType': 'users',
+      'actorId': 'u',
+      'actorDisplayName': 'U',
+      'timestamp': 1700000000,
+      'systemMessage': '',
+      'messageType': 'comment',
+      'isReplyable': true,
+      'referenceId': '',
+      'message': 'hi',
+    },
+};
+
+void main() {
+  setUp(drainDecodeWarnings);
+
+  test('skips a room that does not parse and records class and key', () {
+    final broken = _room()..remove('displayName');
+    final response = GetRoomResponse.fromJson({
+      'data': [broken, _room()],
+    });
+    expect(response.data.length, 1);
+    final warnings = drainDecodeWarnings();
+    expect(warnings, hasLength(1));
+    expect(warnings.single, contains('GetRoomResponseObject'));
+    expect(warnings.single, contains('"displayName"'));
+  });
+
+  test('parses a room whose lastMessage the server omitted', () {
+    final response = GetRoomResponse.fromJson({
+      'data': [_room(withLastMessage: false), _room()],
+    });
+    final rooms = response.data.toList();
+    expect(rooms[0].lastMessage, isNull);
+    expect(rooms[1].lastMessage?.id, 7);
+    expect(drainDecodeWarnings(), isEmpty);
+  });
+
+  test('maps unknown enum values to their fallbacks', () {
+    final room = _room()
+      ..['type'] = 99
+      ..['notificationLevel'] = 42;
+    (room['lastMessage'] as Map<String, dynamic>)
+      ..['actorType'] = 'emails'
+      ..['messageType'] = 'record-video'
+      ..['messageParameters'] = {
+        'actor': {'type': 'deck-card', 'id': '1', 'name': 'Card'},
+      };
+    final parsed = GetRoomResponse.fromJson({
+      'data': [room],
+    }).data.single;
+    expect(parsed.type, GetRoomResponseObjectConversationType.unknown);
+    expect(
+      parsed.notificationLevel,
+      GetRoomResponseObjectParticipantNotificationLevel.defaultLevel,
+    );
+    expect(
+      parsed.lastMessage?.actorType,
+      GetRoomResponseObjectMessageActorType.email,
+    );
+    expect(
+      parsed.lastMessage?.messageType,
+      GetRoomResponseObjectMessageType.unknown,
+    );
+    expect(
+      parsed.lastMessage?.messageParameters?['actor']?.type,
+      RichObjectStringObjectType.unknown,
+    );
+    expect(drainDecodeWarnings(), isEmpty);
+  });
+
+  test('turns a deleted parent into a placeholder', () {
+    final room = _room();
+    (room['lastMessage'] as Map<String, dynamic>)['parent'] = {
+      'id': 3,
+      'deleted': true,
+    };
+    final parent = GetRoomResponse.fromJson({
+      'data': [room],
+    }).data.single.lastMessage?.parent;
+    expect(parent?.id, 3);
+    expect(
+      parent?.messageType,
+      GetRoomResponseObjectMessageType.deletedComment,
+    );
+  });
+}