Remove flutter chat (#26)

Had to squash merge manually as Forgejo was erroring

lib/models/configs/user_config.dart

@@ -0,0 +1,12 @@
+import "package:freezed_annotation/freezed_annotation.dart";
+part "user_config.freezed.dart";
+part "user_config.g.dart";
+
+@freezed
+abstract class UserConfig with _$UserConfig {
+  const factory UserConfig({required String? roomId, required String userId}) =
+      _UserConfig;
+
+  factory UserConfig.fromJson(Map<String, Object?> json) =>
+      _$UserConfigFromJson(json);
+}