Form (+call)

How it works

The submit is a Call message: the form gets a typed promise for its own outcome instead of watching status fields go by. The FIFO mailbox serializes handling, so a double-click queues behind the first submit instead of racing it.

type SignupMsg = Call<{ type: 'submit'; email: string }, { ok: boolean; error?: string }>

// inside the process, a call is an ordinary message carrying reply:
msg.reply(await fakeSignup(msg.email))

// in the view, the answer is just an awaited promise:
const res = await store.call({ type: 'submit', email })