[Other] - Improve Remote Stand Shuttle Bus Operations for Realism

:bullseye: What is your suggestion?
Improve the shuttle bus system for remote stands to make it more realistic.

:hammer_and_wrench: How would it work in the game?

1. For departures: Shuttle buses wait at the gate, leave when full, and make multiple trips until all passengers board the plane.

2.​ For arrivals: Shuttle buses wait at the remote stand before the plane lands, pick up passengers, and return to the terminal in cycles.

​3.The plane door only closes after all passengers are on board and all shuttle buses have left.

:balance_scale: Why is this a good idea?
It makes the game feel more like a real airport.

​Fixes issues where shuttle buses and plane timings don’t match.

Adds more fun and immersion to managing remote stands.