Adds prepared listing JSON to avoid repeated decoding and rebuilding of server payloads on listing reads. Prepared reads are disabled by default and support bounded backfill and flag rollback. Listing rows release their database connection before JSON processing; pool defaults remain 60/10.
Focused response/update/delete/backfill/rollback checks passed. Local encoding benchmarks over saved public records measured 63% less encoding time and 88% fewer allocations. These are encoding-cost results, not a peak-capacity guarantee. Broad staging replay remained inconclusive for capacity due to generator port exhaustion and losses.