M: Manager with action eligibility
C: Create invite record
Q: Attempt invitation queue event
V: Invitee previews supplied code
I: Resolve intended active member
A: Activate code
T: Attach or reactivate team relationship
P: Conditional membership writes
R: Return activation result
M → C
C → Q
C → V
V → I: Valid now
I → A
A → T
A → P
A → R