DECIPHER THE DIGITAL SQUARE.
REQUIRED: 1, 2, 3, 4, 5, 6, 7, 8, 9 (UNIQUE)
> 幻和 (Magic Constant): 1-9 total sum is 45. Each row/col must be 45/3 = 15.
> 中心 (Center): The heart of the matrix. Always 5 for 1-9 grid.
> Corners: Must be even numbers (2, 4, 6, 8) to balance the sums.