v1.0.2 - A mail when your account is ready, sturdier queues

Waitlist users get a mail when their account opens, an existing account cannot land on the waitlist again, and queued work survives the loss of a server.

• A mail when your account is ready. When we open an account for a waitlist address, that address receives a mail with the username and how to sign in with a magic link.
• No second waitlist entry. An address that already has an account is not added to the waitlist again, so a user whose trial has ended is not told to wait for an account they already have.
• Sturdier queues. Chats, reports, translations and mails that are waiting to run are now kept on several servers, so one server going down no longer loses them.