Fix Home Assistant MQTT discovery deprecation warnings

[sevorl]

Summary

This PR fixes Home Assistant Core 2026.4 compatibility warnings

Changes

Home Assistant MQTT Discovery Fix

• Replaced deprecated object_id with default_entity_id in all MQTT discovery messages
• Affects 9 entities: sensors (vehicle connected, vehicle charging, charging power, charging current, charging current limit, energy meter, temperature), switch (enable charging), and number (charging current limit control)
• Resolves deprecation warnings: "The configuration for entity [...] uses the deprecated option object_id"
• Ensures compatibility with Home Assistant Core 2026.4+

Testing

• Successfully built and tested firmware for Lilygo T-CAN485 board
• MQTT discovery messages validated against Home Assistant 2025.11 requirements

References

• Home Assistant MQTT discovery documentation on entity ID configuration
• Related to ongoing Home Assistant Core deprecation timeline (stopping in 2026.4)

From the Home assistant logs:

The configuration for entity sensor.heidelbridge_charging_current uses the deprecated option object_id to set the default entity id. Replace the "object_id": "HeidelBridge_charging_current" option with "default_entity_id": "sensor.HeidelBridge_charging_current" in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4

[BorisBrock]

OK