pub fn start_guard(eviction_callback: Arc<dyn Fn(PressureLevel) + Send + Sync>)Expand description
Start the background memory guardian task (idempotent). Polls every 3s (normal), 1s (under pressure), or up to 15s once RSS has been stably calm (idle backoff). At Critical level, performs aggressive eviction and signals background tasks to abort — never exits the process.