Accept an invitation addressed to you

Accepting is the invited person's own act. Guarded by MEMBERSHIP_LIST - the permission every role holds - because the caller is by definition not yet an active member and cannot be held to a role they have not taken up.

curl -X POST "https://example.com/api/b/v1/members/invitations/accept"

{  "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",  "user_id": "a169451c-8525-4352-b8ca-070dd449a1a5",  "role": "owner",  "status": "invited",  "invited_by": "0fdabe0c-eb7c-440a-96d2-2c65906c3777"}