Native Integration

Full Changelog: https://github.com/CorentinBarban/SmartHRT/commits/v0.1.0

NEW: Complete rewrite as a native Home Assistant custom integration (HACS compatible)
NEW: Configuration via UI flow (no more YAML configuration required)
NEW: Exposed Home Assistant services for automation:
smarthrt.calculate_recovery_time
smarthrt.calculate_recovery_update_time
smarthrt.calculate_rcth_fast
smarthrt.on_heating_stop
smarthrt.on_recovery_start
NEW: Centralized coordinator architecture with SmartHRTData dataclass
NEW: Real-time sensor updates via state change listeners
NEW: Debug logging support for troubleshooting
IMPROVED: Code simplified from ~964 to ~624 lines with better organization
IMPROVED: Factorized interpolation and coefficient update methods