Ruzsa’s genus-one problem

Improves witness#149 from size 23 to 24. Derived from witness#151 (N = 1945, size 29): apply the affine automorphism x -> 1939x + 1158 (mod 1945), reinterpret the resulting residues modulo 1901, then greedily hit all 107 resulting distinct conflict supports. This was transform 772 of transfer-search seed 5805. A second independent affine transfer also produced size 24; a subsequent sweep of 738,870 transfers found no size-25 subset. Independently checked before submission by literal enumeration of all 24^4 = 331,776 ordered quadruples: exactly 24 solutions, all diagonal.