#1039 auth library pool hardcoded (5+5 per process in 3.1.0, 2+2 in 3.3.0): blocks pg-nano highway_app limit 60

EARS: The API's auth library connections shall be bounded by configuration (target 1 per process at cutover). Requested from auth-service-8bf0e2 on 2026-10-20 (AUTH_DATABASE_POOL_SIZE / MAX_OVERFLOW / POOL_TIMEOUT). Until then the pg-nano cutover (#925) cannot meet the 60-connection limit (4 api processes x 10 = 40 for auth alone).