Siege engineers' AIs:

• move vehicles closer to target if needed
• repair vehicles if they are damaged
  • when there's no target to fight and vehicle is damaged dismount and repair
  • if there's no vehicle to use look around for vehicles to fix

Courier AIs:

• deliver items to entities that have inventory (aka vehicles that can use ammo or other stuff)
• mount chest cart / boat
  • be able to drive this between delivery stations
  • needs a new chunk loading upgrade to be able to chunk load on longer routes

Add textures for new AI task types and display those when they're active