deploy/db/init/20-tuning.sql sets the memory budget via ALTER SYSTEM (applied on a
fresh volume, effective after the post-init restart): shared_buffers 2GB,
effective_cache_size 6GB, work_mem 64MB, maintenance_work_mem 512MB, max_wal_size
4GB, plus duckdb.max_memory 4GB for parquet processing.
Compose: the db container gets an 8g memory ceiling + 1g shm_size (parallel-query
shared memory) in prod; the dev overlay resets mem_limit so dev memory is uncapped
too (the ~8 GB budget still comes from the tuning). Verified the settings take
effect and pg_duckdb still loads.
