Signal is publicly testing letting users add usernames to their accounts so they don’t have to share their phone number to connect via the encrypted messaging service. The test was announced via a post on the Signal forums by VP of engineering Jim O’Leary, who referred to the feature as “pre-beta” and warned that there’ll be rough edges including crashes and broken push notifications. An official release is planned for early 2024, Signal president Meredith Whittaker recently…