feat(bookings): show transport routes on map (#384, #587)

Adds from/to endpoints to flight/train/cruise/car reservations with
live map rendering. Flights use geodesic arcs and a curved duration +
distance badge; train/car/cruise render as straight or geodesic lines
with endpoint markers. Airports come from an embedded OurAirports
database (~3200 airports, offline-capable); train/cruise/car locations
via Nominatim. Per-trip connection toggle sits in the day plan
sidebar, persisted in localStorage. Clicking a map endpoint opens the
existing transport detail popup. New display setting toggles endpoint
labels on the map. Migration 105 adds the reservation_endpoints table
plus needs_review flag; existing flights are backfilled from their
IATA metadata on server startup.

server/src/db/database.ts

@@ -128,4 +128,11 @@ function isOwner(tripId: number | string, userId: number): boolean {
   return !!db.prepare('SELECT id FROM trips WHERE id = ? AND user_id = ?').get(tripId, userId);
 }
 
+try {
+  const { backfillFlightEndpoints } = require('../services/airportService');
+  backfillFlightEndpoints();
+} catch (err) {
+  console.error('[DB] Flight endpoint backfill failed:', err);
+}
+
 export { db, closeDb, reinitialize, getPlaceWithTags, canAccessTrip, isOwner };