Download BSSN StateList from GPU to CPU before AHFinderDirect_find_horizons
so that AH_Interp_Points reads valid field data instead of stale CPU arrays.
The resident-sync path keeps canonical state on GPU; without this download the
Newton iteration diverges and probes outside the computational domain.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>