5.6-sol-medium matches 5.5-xhigh performance with 47% cost cut

5.6-sol-medium achieves 16% intended exploits at $19.62, compared to 5.5-xhigh's 15% at $36.80 on the ExploitGym benchmark, representing a 47% cost reduction. The new model appears to be a direct replacement for the older, more expensive variant.