Fix signup crash: click event laundered into username route param

shared/login/join-or-login.tsx

@@ -20,7 +20,7 @@ const Intro = () => {
   const startProvision = useProvisionState(s => s.dispatch.startProvision)
   const requestAutoInvite = useRequestAutoInvite()
   const onLogin = () => startProvision()
-  const onSignup = () => requestAutoInvite()
+  const onSignup = () => requestAutoInvite('')
   const showProxySettings = () => {
     C.Router2.navigateAppend({name: 'proxySettingsModal', params: {}})
   }

shared/login/relogin/container.tsx

@@ -17,7 +17,8 @@ const ReloginContainer = () => {
     C.Router2.navigateAppend({name: 'signupSendFeedbackLoggedOut', params: {}})
   }
   const onLogin = useConfigState(s => s.dispatch.login)
-  const onSignup = useRequestAutoInvite()
+  const requestAutoInvite = useRequestAutoInvite()
+  const onSignup = () => requestAutoInvite('')
   const onSomeoneElse = useProvisionState(s => s.dispatch.startProvision)
   const error = perror?.desc || ''
   const loggedInMap = new Map<string, boolean>(_users.map(account => [account.username, account.hasStoredSecret]))

shared/signup/use-request-auto-invite.tsx

@@ -7,7 +7,7 @@ const useRequestAutoInvite = () => {
   const waiting = C.Waiting.useAnyWaiting(C.waitingKeySignup)
   const {navigateAppend, navigateUp} = C.Router2
 
-  return (username?: string) => {
+  return (username: string) => {
     if (waiting) {
       return
     }