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/files_sharing/file_sharing_api_params.g.dart

@@ -8,16 +8,19 @@ part of 'file_sharing_api_params.dart';
 
 FileSharingApiParams _$FileSharingApiParamsFromJson(
   Map<String, dynamic> json,
-) => FileSharingApiParams(
-  shareType: (json['shareType'] as num).toInt(),
-  shareWith: json['shareWith'] as String,
-  path: json['path'] as String,
-  referenceId: json['referenceId'] as String?,
-  talkMetaData: json['talkMetaData'] as String?,
-  permissions: (json['permissions'] as num?)?.toInt(),
-  password: json['password'] as String?,
-  expireDate: json['expireDate'] as String?,
-);
+) => $checkedCreate('FileSharingApiParams', json, ($checkedConvert) {
+  final val = FileSharingApiParams(
+    shareType: $checkedConvert('shareType', (v) => (v as num).toInt()),
+    shareWith: $checkedConvert('shareWith', (v) => v as String),
+    path: $checkedConvert('path', (v) => v as String),
+    referenceId: $checkedConvert('referenceId', (v) => v as String?),
+    talkMetaData: $checkedConvert('talkMetaData', (v) => v as String?),
+    permissions: $checkedConvert('permissions', (v) => (v as num?)?.toInt()),
+    password: $checkedConvert('password', (v) => v as String?),
+    expireDate: $checkedConvert('expireDate', (v) => v as String?),
+  );
+  return val;
+});
 
 Map<String, dynamic> _$FileSharingApiParamsToJson(
   FileSharingApiParams instance,