v1.6.1

• Version sensor: New sensor.dockge_server_{agent}_version per agent, showing Dockge version
• Device sw_version: Agent device info now includes software version
• Remove auto-cleanup: Stale devices/entities are no longer auto-deleted (prevents agents disappearing during restarts). Users can manually delete from HA Devices page.

Paired with dockge-managed v2.1.1.