pub const MINI_RING: [[usize; 2]; 3];Expand description
Clockwise ring position of each (row, col) cell of the 2×3 mini spinner,
top-left first: (0,0) → (0,1) → (1,1) → (2,1) → (2,0) → (1,0). Every cell of
a 2×3 grid is on the ring, so the brightness chases around it.