{"input":[[2,1,5,6,2,3]],"expected":10,"label":"Classic histogram: max area=5×2=10"}
{"input":[[1,2,3,4,5]],"expected":9,"label":"Ascending: height=3, width=3 → 9"}
{"input":[[5,4,3,2,1]],"expected":9,"label":"Descending: height=3, width=3 → 9"}
{"input":[[2,2,2,2,2]],"expected":10,"label":"All same h=2, w=5 → 10"}
{"input":[[0,0,0,1,0,0,0]],"expected":1,"label":"Single bar surrounded by zeros"}
{"input":[[6,2,5,4,5,1,6]],"expected":12,"label":"Complex: 2 bars of height 6 → 12"}
