Expose public API to find Twitter/Mastodon accounts
A simple public API with two endpoints would be very useful:
/twitter/:username(returns mastodon user ID)
/mastodon/:user_id(returns Twitter username)
This could be used for e.g. Twitter<->Mastodon repost bots that could replace mentions (or even try to find a matching Toots<->Tweets), or integration of the bridge functionality into 3rd party apps.