Always show display name without matrix id
Usually, NeoChat shows the displayname of a user. In cases where multiple users in a room have the same username, the matrixId is appended for clarity. People often join rooms with multiple accounts (e.g., on multiple homeservers) or join a bridged room both from matrix and from the other side, resulting in many situations where we're seeing this. It's especially annoying for bridged users, where the matrix id is often some random string.
I'd propose not showing the matrix id at all in this situation, at least in the timeline.