Update __exclusive__: Kt20-y-multi-v2.0

: Lowered by an average of 1.4W during standby polling phases, increasing the lifespan of isolated battery cells.

The primary focus of the V2.0 update is the refinement of "Multi" capabilities—referring to the device's ability to interface with multiple platforms simultaneously. kt20-y-multi-v2.0 update

Existing Modbus registers and MQTT topics remain unchanged. OPC UA endpoints are new and optional. : Lowered by an average of 1