Bring Conversation Participants Front and Center With Inline Controls

Some updates:

Merge or add as client for Unidentifieds: click a participant to merge into an existing contact, or add them as new if they’re unrecognized

Client hover card: hover over a client to see their contact info, with one-click copy

Agent follow controls: set or remove an agent as a follower directly from the participant chip

Add participant: same flow as before, now using our upgraded selector