Checkmk special agent for Portainer Business Edition license and node monitoring via REST API. Collects and evaluates license expiry (days_left), licensed vs. used nodes (licensed_nodes, used_nodes, node_usage_pct), plus API health/runtime (api_runtime), with configurable warn/crit thresholds and hard CRIT on node overuse (used_nodes > licensed_nodes). Compatible with Checkmk 2.4.0 (CRE/CEE).