SACRAMENTO, Calif. — The long and brutal 2017 wildfire season is stressing the state and federal agencies that have to pay for the army of ground crews and machinery required to fight them. The federal government spent more than $2.7 billion on firefighting in its most recently finished budget year, a record that far surpassed the previous high point of $2.1 billion set just two years ago. …The Forest Service and its parent agency, the Department of Agriculture, have long argued that big wildfires should be treated like hurricanes, floods and other natural disasters and be paid for out of the federal Disaster Relief Fund. That would stabilize the Forest Service budget and help preserve money for fire-prevention programs. Many members of Congress agree — but they disagree on how to go about making the change.