Weather and building decay
BuildingRain wear requires exposed wet susceptible pieces above half health and timer>60s. Support failure sets100% damage; persistent-event, required-biome, Ashlands/lava and DeepNorth heavy-snow rules add damage. Heavy snow uses shelter/shields, accumulated snow, support-color threshold and NoHeavySnow/AllHeavySnow. NoBuildingFall gates final UpdateWear damage.

