Once the username input settles, the field queries `usernameAvailable`
and reports next to it whether the name is available, taken or rejected
by the registration policy. In the two-step layout, continuing is held
back while a settled verdict says the name can't be used. The island now
declares the GraphQL endpoint on its mount node and brings its own query
client.
Quentin Gliech
3a1e62c72b