additionalField type json not included in type

// server setup
export const auth = betterAuth({
  database: new Database("..."),
  emailAndPassword: {
    enabled: true,
    autoSignIn: true,
  },
  basePath: "/xhr/auth",
  trustedOrigins: ["http://localhost:3002", "http://localhost:3003"],
  user: {
    additionalFields: {
      features: {
        type: "json",
        input: false,
      },
      group: {
        type: "string",
        input: false,
      },
    },
  },
  plugins: [
    username(),
    localLoginPlugin({ enforceYamlUsersOnly: true, synthEmailDomain: "local" }),
  ],
});

export type Session = typeof auth.$Infer.Session;

// client setup
export const authClient = createAuthClient({
  baseURL: "http://localhost:3002/xhr/auth",
  plugins: [
    inferAdditionalFields({
      user: {
        features: {
          type: "json",
          input: false,
        },
        group: {
          type: "string",
          input: false,
        },
      },
    }),
    localSignIn(),
  ],
});

// session.user type
(property) user: {
    id: string;
    createdAt: Date;
    updatedAt: Date;
    email: string;
    emailVerified: boolean;
    name: string;
    image?: string | null | undefined;
    group: string;
    username?: string | null | undefined;
    displayUsername?: string | null | undefined;
} | undefined