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

lib/api/marianumcloud/autocomplete/autocomplete_api.dart

@@ -5,6 +5,8 @@ import 'package:http/http.dart' as http;
 import '../../../model/endpoint_data.dart';
 import '../../errors/server_exception.dart';
 import '../../http_errors.dart';
+import '../../json_lenient.dart';
+import '../../marianumconnect/queries/report_client_error/client_error_reporter.dart';
 import '../nextcloud_ocs.dart';
 import 'autocomplete_response.dart';
 
@@ -43,6 +45,13 @@ class AutocompleteApi {
         technicalDetails: 'core/autocomplete/get: ${response.body}',
       );
     }
-    return AutocompleteResponse.fromJson(NextcloudOcs.decode(response.body));
+    final result = AutocompleteResponse.fromJson(
+      NextcloudOcs.decode(response.body),
+    );
+    ClientErrorReporter.reportDecodeWarnings(
+      'Autocomplete',
+      drainDecodeWarnings(),
+    );
+    return result;
   }
 }