Request: Reduce RRD Retention to 6 Months for Observium 25.8.14182

We're using Observium 25.8.14182 to monitor our network, and we would like to configure it so that no performance data (RRD files) or related metrics are kept longer than 6 months.

Currently, Observium appears to retain historical RRD data for several years by default. Before making any configuration changes, we'd like to confirm the officially supported way to limit data retention to 6 months — including any necessary settings in config.php or other files.

Could you please confirm:

1. The correct method to make Observium automatically discard data older than 6 months.

1. Whether it's supported to modify $config['rrd']['rra'] to enforce this retention.

1. If existing RRD files must be rebuilt for this change to take effect.

We haven't made any changes yet — we just want to ensure we follow best practices without causing data loss or corruption.