Created entity_utils/helpers.py with platform-agnostic utility functions:
- get_price_value(): Price unit conversion (major/minor currency)
- translate_level(): Price level translation
- translate_rating_level(): Rating level translation
- find_rolling_hour_center_index(): Rolling hour window calculations
These functions moved from sensor/helpers.py as they are used by both
sensor and binary_sensor platforms. Remaining sensor/helpers.py now
contains only sensor-specific helpers (aggregate_price_data, etc.).
Updated imports:
- sensor/core.py: Import from entity_utils instead of sensor.helpers
- entity_utils/icons.py: Fixed find_rolling_hour_center_index import
- binary_sensor platforms: Can now use shared helpers
Added clear docstrings explaining:
- entity_utils/helpers.py: Platform-agnostic utilities
- sensor/helpers.py: Sensor-specific aggregation functions
Impact: Better code reuse, clearer responsibility boundaries between
platform-specific and shared utilities.
