fix(roadtrip): a booked ferry is driven to, and one without a date says so

A ferry between two stops without a clock was seated by the clock alone, which files a
ride with nothing timed before it at the end of the day. The desktop day list stored that
slot, and the road trip drove overland to the far shore and back to the pier before the
crossing. A ride that leaves and lands on the same day, with both terminals located, now
takes the seat between the clocks that adds the fewest straight-line kilometres. One rule
in shared seats it for the day list, the slot the desktop stores, the phone and PDF lists
and the road trip in the browser and on the server. Slots already stored are left alone.

A flight, train, ferry, cruise or bus on no day made no seam and said nothing, while the
map still drew its arc. The rail and the phone tab now name such a booking with a way to
open it, and calculate_roadtrip lists it under undatedRides.

shared/src/i18n/ja/roadtrip.ts

@@ -277,6 +277,7 @@ const roadtrip: TranslationStrings = {
   'roadtrip.ride.pickup': '受取 {time}',
   'roadtrip.ride.return': '返却 {time}',
   'roadtrip.ride.open': '予約を開く',
+  'roadtrip.ride.undated': '{title} には日付がないため、走行では使われません。',
   'roadtrip.bookings.loose': 'この日のその他の予約',
 };
 export default roadtrip;