Constant CONSUMER_PRODUCTION 

pub const CONSUMER_PRODUCTION: &[(&str, &str)];

Production consumer baseline – lean, only non-defaults.

Setting	Value	librdkafka Default	Why
partition.assignment.strategy	cooperative-sticky	range,roundrobin	KIP-429: avoids stop-the-world rebalances
fetch.min.bytes	1 MiB	1 byte	Batch fetches for throughput
fetch.wait.max.ms	100 ms	500 ms	Bound latency when fetch.min.bytes not met
queued.min.messages	20000	100000	10-20K batches are most efficient
enable.auto.commit	false	true	DFE services manage offset commits
statistics.interval.ms	1000 ms	0 (disabled)	Enable Prometheus metrics