Implement chat server auth, models, handlers, and docs context

lib/src/auth/auth_middleware.dart

@@ -1,7 +1,5 @@
 import 'package:relic/relic.dart';
 
-import '../../config/config.dart';
-import '../utils/extensions.dart';
 import 'crypto_service.dart';
 
 final userIdProperty = ContextProperty<String>('userId');