Follow-up to #491 (#490). The waitlist queue no longer holds people who are already in, and approving one never races another invite.
- Invites settle requests. An invite made for a waiting address (Invite a friend, or a workspace or repository invitation) marks the request invited, approved by whoever sent it (
@friend), with that invite. - Accounts settle requests. An account made with a waiting address marks the request too.
- Asking when already in. Someone who asks for access while already holding an account or a pending invite is marked at once. They get no confirmation email and appear in no staff summary.
- Joined as also finds the account by its address when it came in through a different invite from the request's own.
Only identity changes, plus a note in sudo's README. No migration.
Checked: cargo test -p g1t-identity --lib (237 pass, including a new test for who an answering invite names) and identity's wasm32 check.