{"input":[[1,8,6,2,5,4,8,3,7]],"expected":49,"label":"Classic: height=7, width=7 → 49"}
{"input":[[1,1]],"expected":1,"label":"Two bars h=1,w=1 → 1"}
{"input":[[4,3,2,1,4]],"expected":16,"label":"Symmetric ends h=4, w=4 → 16"}
{"input":[[1,2,1]],"expected":2,"label":"Peak in middle: min(1,1)*2=2"}
