Scaffold SRNE ESS bundle

[tushabe]

What changed

• adds the io.openems.edge.ess.srne Bnd bundle and registers it in EdgeApp
• scaffolds the ESS, grid meter, backup meter, battery inverter/state-machine, charger, common, and enum packages
• adds the initial SRNE ESS OSGi/Modbus component configuration with slave address 1
• ports the validated machine-state blueprint, explicitly marking only state 2 (running (mains/bypass)) as live-verified
• adds a dummy-Modbus activation test and a regression assertion for the validated state

Why

This establishes the structural foundation for the SRNE ASP48120SH3 OpenEMS integration. Register mapping and write control remain intentionally deferred to follow-up stories.

Related to Nearly-Free-Energy/nfe-modbus-energy-logger#15.

Validation

• ./gradlew :io.openems.edge.ess.srne:build
• ./gradlew :io.openems.edge.ess.srne:test :io.openems.edge.ess.srne:checkstyleMain :io.openems.edge.ess.srne:checkstyleTest
• git diff --check

The broader :io.openems.edge.application:resolve check was attempted but the synchronized develop baseline currently cannot resolve io.openems.core.logger; the SRNE bundle build itself is successful.

[tushabe]

@arindahills Story 15 is ready for your review. The SRNE bundle builds locally, its tests and checkstyle pass, and both GitHub Java/UI checks are green. Please review and merge when you are satisfied with the scaffold.