v2.9.0 Various improvements and fix for deprecation warning

Changelog 2.9.0

Fixed

• Home Assistant 2026.8 Compatibility: Added config_entry parameter to DataUpdateCoordinator initialization to resolve ContextVar deprecation warning and ensure compatibility with future Home Assistant versions
• Unload Function: Simplified async_unload_config_entry function by removing non-existent set_querying_state method call that was causing errors during integration unload
• Device Removal: Enhanced async_remove_config_entry_device function with proper null checking and user notification when devices are removed
• AttributeError Fix: Fixed AttributeError: 'NoneType' object has no attribute 'hex' crash in ecu_api.py when inverter raw data is None but code attempts to log it using .hex() method
• Default state Fix: Fixed number entity state defaulting to 0 for maximum inverter power (now 20-500) and switch entity state inverter on/off state after initial hub addition