geoCubic is upside down 🔄

[Fil]

unit test	reality (edit: on Chrome)

(I am completely puzzled)

[Fil]

OK, this is due to numerical instability when computing:

const c = geoCentroid({
    type:"Polygon", 
    coordinates: [[[0,35.264389682754654],[-90,35.264389682754654],[180,35.264389682754654],[90,35.264389682754654],[0,35.264389682754654]]
  ]
  })

on node, Safari, and Firefox, as tested today, this gives c = [0, 90], but in Chrome it's c = [180, 90]. Both are fine, but our code then rotates by [-c[0], -c[1]] which puts the map upside-down.