class DoublePuppetClient
A Client subclass that authenticates with a user's double puppet token instead of the appservice's as_token.
This allows the bridge to send events as the real Matrix user rather than as the appservice bot or a ghost user.
puppet = DoublePuppetClient.new(config, double_puppet_token: "syt_...")
puppet.send_text("!room:example.com", "sent as the real user")
puppet.whoami # => "user_id" => "@alice:example.com"