B1GlobalCityTravelData

• Global (singleton) city-travel state. Saved.
  * The save location (manager serialization vs a separate scope) is to be finalized after the global-data work.

Property	Type	Description	Metadata
bTravelInProgress	bool	Whether a travel is in progress. Single source of truth for mutual exclusion (blocking city move / a new travel).
Active	FB1CityTravelData	Data for the currently in-progress travel. Only meaningful while bTravelInProgress is true.
TravelHouseholdInfoBuffer	TArray	Carry buffer for registering the travel group's household(s) into the UI. Travel moves only the companions, not the household entities, so the destination's B1 HouseholdManager has no household and UI such as Zoi cards breaks. At departure, a distinct FB1HouseholdInfo per household is captured and flush-registered on arrival. Same-city travel is already registered, so this is unused.