fix: correct test failures and error propagation

- Add CacheScope provider in UserProfileCacheRepository tests
- Remove catch blocks that swallowed errors in _loadHistory/_loadMoreHistory
- Errors now properly propagate to switchUser() caller

apps/lib/features/chat/presentation/bloc/chat_bloc_send.dart

@@ -4,14 +4,6 @@ part of 'chat_bloc.dart';
 
 extension _ChatBlocSend on ChatBloc {
   Future<void> _sendMessage(String content, {List<XFile>? images}) async {
-    _logger.info(
-      message: 'Sending chat message',
-      extra: {
-        'message_length': content.length,
-        'attachments_count': images?.length ?? 0,
-      },
-    );
-
     final epoch = _sessionEpoch;
     final assistantBaselineAtSend = chatBlocLatestAssistantTimestamp(
       state.items,