Prompt

Resume the covering bound hunt from problems/covering/compute/q13/CLAIM.md. Certify

via QM$_4^3$ with $m=6$ from the existing 817-column radius-3 seed. Construct and verify a 34-block $(3,0)$-partition, refine it to at most 65 blocks, and check the construction identity plus the seed partition exhaustively without a $2^{44}$ syndrome sweep. The published comparison is 52415. Keep the replay RAM-light, update the notebook and model ledger, commit the result, and open an unmerged pull request.