fix(mobile): booking routes on the phone map follow the day they run on

A booking switched on with "On map" stayed drawn on every day of the
phone's plan map, so a flight from the first day crossed the map of the
third, although a day chip frames one day and drops the other days' pins.
The plan map now draws such a booking only on the days it runs on, the
arrival day of an overnight one included, and the all-days view still
shows every booking that is switched on. The switch itself stays
trip-wide, and the desktop, collections and the road trip stage draw
exactly as before.

"On map" in a booking's sheet now reads as on only where the plan map
draws the route. From any other day a tap takes the map to the booking's
day, switching the route on when it is off, instead of hiding a route
that is not drawn there anyway.

The phone settings also gain the "Always show booking routes" switch the
desktop already had. As on the desktop it sets the default for trips not
yet touched on this device, so a trip where a route was switched on or
off by hand keeps that choice.

wiki/Map-Features.md

@@ -93,6 +93,8 @@ Flights, trains, cars, and cruises can be drawn as overlays between their endpoi
 - **Show all / hide all** — a route icon button in the day-plan toolbar (next to Undo/Reorder) flips the whole trip between showing every routable booking and showing none. It is a clean slate rather than a layer on top: whatever you had set with the per-booking **Route** icons is discarded, so pressing it twice leaves you with all routes on or all off, not back where you started. (Automated public-transit journeys have a second gate of their own — see the transit bullet.)
 - **Always show booking routes** (Settings → General → Travel & map) — an account-wide default that shows every booking's route automatically on any trip you haven't touched before. It sets the *default* only — a trip where you've already used the per-booking toggle or the bulk button keeps its own choice even if you change this setting afterwards.
 
+On a phone the plan map shows one day at a time, so a booking you have switched on is drawn there only on the days it runs on, the arrival day of an overnight journey included, and in the all-days view. The **On map** button in a booking's detail sheet reads as on only where the route is drawn; from any other day it takes the map to the booking's own day instead of hiding the route. The desktop map and the road trip stage keep drawing a switched-on booking on every day.
+
 > **Tip:** Whether endpoint text labels appear on the endpoint markers is your own choice — the **Booking route labels** setting in Settings → General → Travel & map (`map_booking_labels`). It is off by default; with it off, the endpoint markers show only the transport icon.
 
 ## Plugin map markers