Add Participant

Not sure if this is an issue with functionality or an issue with the UI. Depends on what your intent is I suppose.

If I have a group chat already started, the info icon gives me the option to add a participant. But then it doesn't actually let me add a participant, it only lets me create a whole new fresh chat with existing group plus that new participant.

Is that how it's supposed to work? The UI suggests I should be able to add to existing. Not create new.

No files, tests, or entry points are identified. Reproduce the group-chat info flow and inspect how the Add Participant action handles an existing group; done means the UI behavior and resulting chat match the intended participant-addition behavior.

Written by the indexing model from the issue text.