Space invites now pick from your org, not an open email field

Adding someone to a Space now shows a dropdown of people already in your org instead of a free-text email field, so you can no longer accidentally invite someone from outside the org into a Space. Picking a member and a role adds them right away — no email or sign-in link involved — and if everyone in the org is already in the Space, the dialog points you to the team members page to bring someone new into the org first. Bringing brand-new people into the org itself is still done from Plan & team, unchanged.