refactor(vacay): share the fusion invite picker between desktop and phone

Loading the users that can be invited, the picked user and sending the invite with its toasts now live in useVacayUserPicker. The dialog still resets and closes on success, the sheet still closes and resets on the next open and empties the list when loading fails.

client/src/mobile/screens/vacay/MVacayInviteSheet.tsx

@@ -4,9 +4,8 @@ import MSheet from '../../components/MSheet'
 import MIconBtn from '../../components/MIconBtn'
 import { useVacayStore } from '../../../store/vacayStore'
 import { useTranslation } from '../../../i18n'
-import { useToast } from '../../../components/shared/Toast'
-import { getApiErrorMessage, type VacayUser } from '../../../types'
-import apiClient from '../../../api/client'
+import { type VacayUser } from '../../../types'
+import { useVacayUserPicker } from '../../../components/Vacay/useVacayUserPicker'
 
 interface MVacayInviteSheetProps {
   open: boolean
@@ -20,37 +19,24 @@ interface MVacayInviteSheetProps {
  */
 export default function MVacayInviteSheet({ open, onClose }: MVacayInviteSheetProps) {
   const { t } = useTranslation()
-  const toast = useToast()
   const { invite, pendingInvites, cancelInvite } = useVacayStore()
-  const [available, setAvailable] = useState<VacayUser[]>([])
-  const [selected, setSelected] = useState<number | null>(null)
+  const { available, selected, setSelected, selectedUser, sending, load, send } = useVacayUserPicker<VacayUser>({
+    endpoint: '/addons/vacay/available-users',
+    submit: invite,
+    successKey: 'vacay.inviteSent',
+    errorKey: 'vacay.inviteError',
+    clearOnLoadError: true,
+  })
   const [pickerOpen, setPickerOpen] = useState(false)
-  const [sending, setSending] = useState(false)
 
   useEffect(() => {
     if (!open) return
     setSelected(null)
     setPickerOpen(false)
-    apiClient.get('/addons/vacay/available-users')
-      .then(r => setAvailable(r.data.users))
-      .catch(() => setAvailable([]))
-  }, [open])
+    void load()
+  }, [open, setSelected, load])
 
-  const selectedUser = available.find(u => u.id === selected)
-
-  const handleSend = async () => {
-    if (!selected) return
-    setSending(true)
-    try {
-      await invite(selected)
-      toast.success(t('vacay.inviteSent'))
-      onClose()
-    } catch (err: unknown) {
-      toast.error(getApiErrorMessage(err, t('vacay.inviteError')))
-    } finally {
-      setSending(false)
-    }
-  }
+  const handleSend = () => send(onClose)
 
   return (
     <MSheet open={open} onClose={onClose} variant="card" material="glass" ariaLabel={t('vacay.inviteUser')}>