Add AquaTemp hot-water power controls and controller modes

[undecomposed]

Summary

• Add Home Assistant Heat/Off controls for supported AquaTemp hot-water controllers.
• Add Intelligent, Eco, Hybrid, and Fast Heating controller presets.
• Preserve the selected preset when controls or automations turn heating on.
• Expose climate-native controls in the Home Assistant UI and reduce duplicated command handling.
• Modernise Python 3.14+ tooling, CI, and pre-commit configuration.

Validation

• Full pre-commit suite completed with Python 3.14.7.
• Python compilation and JSON validation completed.
• Live Home Assistant/cloud checks confirmed Heat, Off, and each controller mode updates the integration state.