Artifact: BLUF Status Update — Shipment API Latency

Shipment API p99 latency spike -- BLUF status update -- exercises co-01.

Decision needed today: approve raising shipment_db's connection-pool size from 20 to 40. Root cause of this morning's p99 latency spike: the pool maxes out during the 09:00-10:00 order-ingestion burst, so requests queue for a free connection instead of failing fast or running normally. DB query plan and the ParcelLink carrier lookup are both ruled out -- neither shows any regression.

Investigation notes (for reference): checked EXPLAIN ANALYZE on the main query first (indexes in use, no regression); checked ParcelLink's status page for a carrier-side incident (none reported); found the connection-pool metrics maxing out during the ingestion burst.